From 5a55978478bca98115bd274560e2cbbb15d347b1 Mon Sep 17 00:00:00 2001
From: Julian Descottes <jdescottes@mozilla.com>
Date: Wed, 27 Mar 2019 12:12:55 +0000
Subject: [PATCH 01/59] style: Augment CSS errors with the CSS selector.

Differential Revision: https://phabricator.services.mozilla.com/D24894
---
 components/style/error_reporting.rs              | 6 ++++--
 components/style/properties/declaration_block.rs | 8 ++++++--
 components/style/stylesheets/rule_parser.rs      | 6 +++---
 3 files changed, 13 insertions(+), 7 deletions(-)

diff --git a/components/style/error_reporting.rs b/components/style/error_reporting.rs
index c58964c057a..9d54f62e318 100644
--- a/components/style/error_reporting.rs
+++ b/components/style/error_reporting.rs
@@ -10,12 +10,14 @@ use crate::stylesheets::UrlExtraData;
 use cssparser::{BasicParseErrorKind, ParseErrorKind, SourceLocation, Token};
 use std::fmt;
 use style_traits::ParseError;
+use crate::selector_parser::{SelectorImpl};
+use selectors::SelectorList;
 
 /// Errors that can be encountered while parsing CSS.
 #[derive(Debug)]
 pub enum ContextualParseError<'a> {
     /// A property declaration was not recognized.
-    UnsupportedPropertyDeclaration(&'a str, ParseError<'a>),
+    UnsupportedPropertyDeclaration(&'a str, ParseError<'a>, Option<&'a SelectorList<SelectorImpl>>),
     /// A font face descriptor was not recognized.
     UnsupportedFontFaceDescriptor(&'a str, ParseError<'a>),
     /// A font feature values descriptor was not recognized.
@@ -121,7 +123,7 @@ impl<'a> fmt::Display for ContextualParseError<'a> {
         }
 
         match *self {
-            ContextualParseError::UnsupportedPropertyDeclaration(decl, ref err) => {
+            ContextualParseError::UnsupportedPropertyDeclaration(decl, ref err, _selectors) => {
                 write!(f, "Unsupported property declaration: '{}', ", decl)?;
                 parse_error_to_str(err, f)
             },
diff --git a/components/style/properties/declaration_block.rs b/components/style/properties/declaration_block.rs
index e4396e764a4..5a2fd6f2236 100644
--- a/components/style/properties/declaration_block.rs
+++ b/components/style/properties/declaration_block.rs
@@ -25,6 +25,8 @@ use style_traits::{CssWriter, ParseError, ParsingMode, StyleParseErrorKind, ToCs
 use crate::stylesheets::{CssRuleType, Origin, UrlExtraData};
 use super::*;
 use crate::values::computed::Context;
+use crate::selector_parser::{SelectorImpl};
+use selectors::SelectorList;
 
 /// The animation rules.
 ///
@@ -1211,7 +1213,7 @@ pub fn parse_style_attribute(
     );
 
     let mut input = ParserInput::new(input);
-    parse_property_declaration_list(&context, &mut Parser::new(&mut input))
+    parse_property_declaration_list(&context, &mut Parser::new(&mut input), None)
 }
 
 /// Parse a given property declaration. Can result in multiple
@@ -1248,6 +1250,7 @@ pub fn parse_one_declaration_into(
         let error = ContextualParseError::UnsupportedPropertyDeclaration(
             parser.slice_from(start_position),
             err,
+            None
         );
         context.log_css_error(location, error);
     })
@@ -1312,6 +1315,7 @@ impl<'a, 'b, 'i> DeclarationParser<'i> for PropertyDeclarationParser<'a, 'b> {
 pub fn parse_property_declaration_list(
     context: &ParserContext,
     input: &mut Parser,
+    selectors: Option<&SelectorList<SelectorImpl>>
 ) -> PropertyDeclarationBlock {
     let mut declarations = SourcePropertyDeclaration::new();
     let mut block = PropertyDeclarationBlock::new();
@@ -1338,7 +1342,7 @@ pub fn parse_property_declaration_list(
                 }
 
                 let location = error.location;
-                let error = ContextualParseError::UnsupportedPropertyDeclaration(slice, error);
+                let error = ContextualParseError::UnsupportedPropertyDeclaration(slice, error, selectors);
                 context.log_css_error(location, error);
             }
         }
diff --git a/components/style/stylesheets/rule_parser.rs b/components/style/stylesheets/rule_parser.rs
index a780ebce250..8f4cb088cf0 100644
--- a/components/style/stylesheets/rule_parser.rs
+++ b/components/style/stylesheets/rule_parser.rs
@@ -9,7 +9,7 @@ use crate::error_reporting::ContextualParseError;
 use crate::font_face::parse_font_face_block;
 use crate::media_queries::MediaList;
 use crate::parser::{Parse, ParserContext};
-use crate::properties::parse_property_declaration_list;
+use crate::properties::{parse_property_declaration_list};
 use crate::selector_parser::{SelectorImpl, SelectorParser};
 use crate::shared_lock::{Locked, SharedRwLock};
 use crate::str::starts_with_ignore_ascii_case;
@@ -548,7 +548,7 @@ impl<'a, 'b, 'i> AtRuleParser<'i> for NestedRuleParser<'a, 'b> {
                     self.namespaces,
                 );
 
-                let declarations = parse_property_declaration_list(&context, input);
+                let declarations = parse_property_declaration_list(&context, input, None);
                 Ok(CssRule::Page(Arc::new(self.shared_lock.wrap(PageRule {
                     block: Arc::new(self.shared_lock.wrap(declarations)),
                     source_location,
@@ -596,7 +596,7 @@ impl<'a, 'b, 'i> QualifiedRuleParser<'i> for NestedRuleParser<'a, 'b> {
         let context =
             ParserContext::new_with_rule_type(self.context, CssRuleType::Style, self.namespaces);
 
-        let declarations = parse_property_declaration_list(&context, input);
+        let declarations = parse_property_declaration_list(&context, input, Some(&selectors));
         let block = Arc::new(self.shared_lock.wrap(declarations));
         Ok(CssRule::Style(Arc::new(self.shared_lock.wrap(StyleRule {
             selectors,

From 1f73c524bd240ece2db99ef39f5f4441742cb06b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Emilio=20Cobos=20=C3=81lvarez?= <emilio@crisal.io>
Date: Wed, 27 Mar 2019 15:03:20 +0000
Subject: [PATCH 02/59] style: Follow the list-item definition from the spec a
 bit more closely.

The HTML restriction doesn't match any browser.

This matches Edge, though I filed
https://github.com/w3c/csswg-drafts/issues/3766 about the pseudo-element
condition.

Differential Revision: https://phabricator.services.mozilla.com/D24936
---
 components/style/style_adjuster.rs | 10 ++--------
 1 file changed, 2 insertions(+), 8 deletions(-)

diff --git a/components/style/style_adjuster.rs b/components/style/style_adjuster.rs
index 070a2299969..91e4bba992b 100644
--- a/components/style/style_adjuster.rs
+++ b/components/style/style_adjuster.rs
@@ -728,10 +728,7 @@ impl<'a, 'b: 'a> StyleAdjuster<'a, 'b> {
     ///
     /// https://drafts.csswg.org/css-lists-3/#declaring-a-list-item
     #[cfg(feature = "gecko")]
-    fn adjust_for_list_item<E>(&mut self, element: Option<E>)
-    where
-        E: TElement,
-    {
+    fn adjust_for_list_item(&mut self) {
         use crate::properties::longhands::counter_increment::computed_value::T as ComputedIncrement;
         use crate::values::generics::counters::CounterPair;
         use crate::values::specified::list::MozListReversed;
@@ -743,9 +740,6 @@ impl<'a, 'b: 'a> StyleAdjuster<'a, 'b> {
         if self.style.pseudo.is_some() {
             return;
         }
-        if !element.map_or(false, |e| e.is_html_element()) {
-            return;
-        }
         // Note that we map <li value=INTEGER> to 'counter-set: list-item INTEGER;
         // counter-increment: list-item 0;' so we'll return here unless the author
         // explicitly specified something else.
@@ -833,7 +827,7 @@ impl<'a, 'b: 'a> StyleAdjuster<'a, 'b> {
         #[cfg(feature = "gecko")]
         {
             self.adjust_for_appearance(element);
-            self.adjust_for_list_item(element);
+            self.adjust_for_list_item();
         }
         self.set_bits();
     }

From 76c0ae565eef1408fc3f1c99d99fa532172793cb Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Emilio=20Cobos=20=C3=81lvarez?= <emilio@crisal.io>
Date: Thu, 28 Mar 2019 13:50:13 +0000
Subject: [PATCH 03/59] style: Fix ::marker invalidation when we need to
 potentially insert a marker as a result of a style change.

Differential Revision: https://phabricator.services.mozilla.com/D24888
---
 .../style/invalidation/element/invalidator.rs     | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/components/style/invalidation/element/invalidator.rs b/components/style/invalidation/element/invalidator.rs
index 7ed97c0b197..371c0771183 100644
--- a/components/style/invalidation/element/invalidator.rs
+++ b/components/style/invalidation/element/invalidator.rs
@@ -750,8 +750,19 @@ where
                     //
                     // Note that we'll also restyle the pseudo-element because
                     // it would match this invalidation.
-                    if self.processor.invalidates_on_eager_pseudo_element() && pseudo.is_eager() {
-                        invalidated_self = true;
+                    if self.processor.invalidates_on_eager_pseudo_element() {
+                        if pseudo.is_eager() {
+                            invalidated_self = true;
+                        }
+                        // If we start or stop matching some marker rules, and
+                        // don't have a marker, then we need to restyle the
+                        // element to potentially create one.
+                        //
+                        // Same caveats as for other eager pseudos apply, this
+                        // could be more fine-grained.
+                        if pseudo.is_marker() && self.element.marker_pseudo_element().is_none() {
+                            invalidated_self = true;
+                        }
                     }
                 }
 

From bd77cd64b93e528fe50d5b1f04756ca02f9a5ad4 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Emilio=20Cobos=20=C3=81lvarez?= <emilio@crisal.io>
Date: Fri, 29 Mar 2019 11:12:12 +0000
Subject: [PATCH 04/59] style: Refactor some enabledness checks.

There are some common checks that could get some easy-to-use aliases.

Differential Revision: https://phabricator.services.mozilla.com/D25117
---
 .../media_queries/media_feature_expression.rs |   3 +-
 components/style/parser.rs                    |  13 ++
 components/style/stylesheets/supports_rule.rs |   3 +-
 components/style/values/specified/box.rs      | 197 +++++++++---------
 4 files changed, 111 insertions(+), 105 deletions(-)

diff --git a/components/style/media_queries/media_feature_expression.rs b/components/style/media_queries/media_feature_expression.rs
index 6a9db93e889..53e24ae5b17 100644
--- a/components/style/media_queries/media_feature_expression.rs
+++ b/components/style/media_queries/media_feature_expression.rs
@@ -17,7 +17,6 @@ use crate::parser::{Parse, ParserContext};
 #[cfg(feature = "servo")]
 use crate::servo::media_queries::MEDIA_FEATURES;
 use crate::str::{starts_with_ignore_ascii_case, string_as_ascii_lowercase};
-use crate::stylesheets::Origin;
 use crate::values::computed::{self, ToComputedValue};
 use crate::values::specified::{Integer, Length, Number, Resolution};
 use crate::values::{serialize_atom_identifier, CSSFloat};
@@ -290,7 +289,7 @@ impl MediaFeatureExpression {
 
             let mut requirements = ParsingRequirements::empty();
 
-            if context.chrome_rules_enabled() || context.stylesheet_origin == Origin::UserAgent {
+            if context.in_ua_or_chrome_sheet() {
                 requirements.insert(ParsingRequirements::CHROME_AND_UA_ONLY);
             }
 
diff --git a/components/style/parser.rs b/components/style/parser.rs
index 6e9d4496cd7..f3190f7f72b 100644
--- a/components/style/parser.rs
+++ b/components/style/parser.rs
@@ -146,10 +146,23 @@ impl<'a> ParserContext<'a> {
         error_reporter.report_error(self.url_data, location, error)
     }
 
+    /// Whether we're in a user-agent stylesheet.
+    #[inline]
+    pub fn in_ua_sheet(&self) -> bool {
+        self.stylesheet_origin == Origin::UserAgent
+    }
+
     /// Returns whether chrome-only rules should be parsed.
+    #[inline]
     pub fn chrome_rules_enabled(&self) -> bool {
         self.url_data.is_chrome() || self.stylesheet_origin == Origin::User
     }
+
+    /// Whether we're in a user-agent stylesheet or chrome rules are enabled.
+    #[inline]
+    pub fn in_ua_or_chrome_sheet(&self) -> bool {
+        self.in_ua_sheet() || self.chrome_rules_enabled()
+    }
 }
 
 /// A trait to abstract parsing of a specified value given a `ParserContext` and
diff --git a/components/style/stylesheets/supports_rule.rs b/components/style/stylesheets/supports_rule.rs
index 45f6f97812d..3ed0595aa44 100644
--- a/components/style/stylesheets/supports_rule.rs
+++ b/components/style/stylesheets/supports_rule.rs
@@ -223,8 +223,7 @@ impl SupportsCondition {
 #[cfg(feature = "gecko")]
 fn eval_moz_bool_pref(name: &CStr, cx: &ParserContext) -> bool {
     use crate::gecko_bindings::bindings;
-    use crate::stylesheets::Origin;
-    if cx.stylesheet_origin != Origin::UserAgent && !cx.chrome_rules_enabled() {
+    if !cx.in_ua_or_chrome_sheet() {
         return false;
     }
     unsafe { bindings::Gecko_GetBoolPrefValue(name.as_ptr()) }
diff --git a/components/style/values/specified/box.rs b/components/style/values/specified/box.rs
index ab81d4c3450..11ab02f045f 100644
--- a/components/style/values/specified/box.rs
+++ b/components/style/values/specified/box.rs
@@ -21,22 +21,17 @@ use std::fmt::{self, Write};
 use style_traits::{CssWriter, KeywordsCollectFn, ParseError};
 use style_traits::{SpecifiedValueInfo, StyleParseErrorKind, ToCss};
 
-fn in_ua_or_chrome_sheet(context: &ParserContext) -> bool {
-    use crate::stylesheets::Origin;
-    context.stylesheet_origin == Origin::UserAgent || context.chrome_rules_enabled()
-}
-
 #[cfg(feature = "gecko")]
 fn moz_display_values_enabled(context: &ParserContext) -> bool {
     use crate::gecko_bindings::structs;
-    in_ua_or_chrome_sheet(context) ||
+    context.in_ua_or_chrome_sheet() ||
         unsafe { structs::StaticPrefs_sVarCache_layout_css_xul_display_values_content_enabled }
 }
 
 #[cfg(feature = "gecko")]
 fn moz_box_display_values_enabled(context: &ParserContext) -> bool {
     use crate::gecko_bindings::structs;
-    in_ua_or_chrome_sheet(context) ||
+    context.in_ua_or_chrome_sheet() ||
         unsafe {
             structs::StaticPrefs_sVarCache_layout_css_xul_box_display_values_content_enabled
         }
@@ -988,27 +983,27 @@ pub enum Appearance {
     /// A typical dialog button.
     Button,
     /// Various arrows that go in buttons
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     ButtonArrowDown,
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     ButtonArrowNext,
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     ButtonArrowPrevious,
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     ButtonArrowUp,
     /// A rectangular button that contains complex content
     /// like images (e.g. HTML <button> elements)
     ButtonBevel,
     /// The focus outline box inside of a button.
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     ButtonFocus,
     /// The caret of a text area
     Caret,
     /// A dual toolbar button (e.g., a Back button with a dropdown)
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     Dualbutton,
     /// A groupbox.
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     Groupbox,
     /// A inner-spin button.
     InnerSpinButton,
@@ -1017,17 +1012,17 @@ pub enum Appearance {
     /// A listbox item.
     Listitem,
     /// Menu Bar background
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     Menubar,
     /// <menu> and <menuitem> appearances
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     Menuitem,
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     Checkmenuitem,
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     Radiomenuitem,
     /// For text on non-iconic menuitems only
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     Menuitemtext,
     /// A dropdown list.
     Menulist,
@@ -1038,28 +1033,28 @@ pub enum Appearance {
     /// An editable textfield with a dropdown list (a combobox).
     MenulistTextfield,
     /// Menu Popup background.
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     Menupopup,
     /// menu checkbox/radio appearances
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     Menucheckbox,
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     Menuradio,
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     Menuseparator,
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     Menuarrow,
     /// An image in the menu gutter, like in bookmarks or history.
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     Menuimage,
     /// A horizontal meter bar.
     #[parse(aliases = "meterbar")]
     Meter,
     /// The meter bar's meter indicator.
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     Meterchunk,
     /// The "arrowed" part of the dropdown button that open up a dropdown list.
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     MozMenulistButton,
     /// For HTML's <input type=number>
     NumberInput,
@@ -1067,7 +1062,7 @@ pub enum Appearance {
     #[parse(aliases = "progressbar")]
     ProgressBar,
     /// The progress bar's progress indicator
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     Progresschunk,
     /// A vertical progress bar.
     ProgressbarVertical,
@@ -1077,25 +1072,25 @@ pub enum Appearance {
     Radio,
     /// A generic container that always repaints on state changes. This is a
     /// hack to make XUL checkboxes and radio buttons work.
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     CheckboxContainer,
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     RadioContainer,
     /// The label part of a checkbox or radio button, used for painting a focus
     /// outline.
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     CheckboxLabel,
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     RadioLabel,
     /// nsRangeFrame and its subparts
     Range,
     RangeThumb,
     /// The resizer background area in a status bar for the resizer widget in
     /// the corner of a window.
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     Resizerpanel,
     /// The resizer itself.
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     Resizer,
     /// A slider.
     ScaleHorizontal,
@@ -1109,26 +1104,26 @@ pub enum Appearance {
     /// The ticks for a slider.
     Scalethumbtick,
     /// A scrollbar.
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     Scrollbar,
     /// A small scrollbar.
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     ScrollbarSmall,
     /// The scrollbar slider
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     ScrollbarHorizontal,
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     ScrollbarVertical,
     /// A scrollbar button (up/down/left/right).
     /// Keep these in order (some code casts these values to `int` in order to
     /// compare them against each other).
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     ScrollbarbuttonUp,
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     ScrollbarbuttonDown,
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     ScrollbarbuttonLeft,
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     ScrollbarbuttonRight,
     /// The scrollbar thumb.
     ScrollbarthumbHorizontal,
@@ -1137,47 +1132,47 @@ pub enum Appearance {
     ScrollbartrackHorizontal,
     ScrollbartrackVertical,
     /// The scroll corner
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     Scrollcorner,
     /// A searchfield.
     Searchfield,
     /// A separator.  Can be horizontal or vertical.
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     Separator,
     /// A spin control (up/down control for time/date pickers).
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     Spinner,
     /// The up button of a spin control.
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     SpinnerUpbutton,
     /// The down button of a spin control.
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     SpinnerDownbutton,
     /// The textfield of a spin control
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     SpinnerTextfield,
     /// A splitter.  Can be horizontal or vertical.
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     Splitter,
     /// A status bar in a main application window.
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     Statusbar,
     /// A single pane of a status bar.
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     Statusbarpanel,
     /// A single tab in a tab widget.
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     Tab,
     /// A single pane (inside the tabpanels container).
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     Tabpanel,
     /// The tab panels container.
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     Tabpanels,
     /// The tabs scroll arrows (left/right).
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     TabScrollArrowBack,
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     TabScrollArrowForward,
     /// A multi-line text field, e.g. HTML <textarea>.
     #[parse(aliases = "textfield-multiline")]
@@ -1185,119 +1180,119 @@ pub enum Appearance {
     /// A single-line text field, e.g. HTML <input type=text>.
     Textfield,
     /// A toolbar in an application window.
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     Toolbar,
     /// A single toolbar button (with no associated dropdown).
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     Toolbarbutton,
     /// The dropdown portion of a toolbar button
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     ToolbarbuttonDropdown,
     /// The gripper for a toolbar.
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     Toolbargripper,
     /// The toolbox that contains the toolbars.
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     Toolbox,
     /// A tooltip.
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     Tooltip,
     /// A listbox or tree widget header
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     Treeheader,
     /// An individual header cell
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     Treeheadercell,
     /// The sort arrow for a header.
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     Treeheadersortarrow,
     /// A tree item.
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     Treeitem,
     /// A tree widget branch line
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     Treeline,
     /// A tree widget twisty.
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     Treetwisty,
     /// Open tree widget twisty.
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     Treetwistyopen,
     /// A tree widget.
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     Treeview,
     /// Window and dialog backgrounds.
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     Window,
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     Dialog,
 
     /// Vista Rebars.
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     MozWinCommunicationsToolbox,
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     MozWinMediaToolbox,
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     MozWinBrowsertabbarToolbox,
     /// Vista glass.
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     MozWinGlass,
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     MozWinBorderlessGlass,
     /// -moz-apperance style used in setting proper glass margins.
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     MozWinExcludeGlass,
 
     /// Titlebar elements on the Mac.
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     MozMacFullscreenButton,
     /// Mac help button.
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     MozMacHelpButton,
 
     /// Windows themed window frame elements.
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     MozWindowButtonBox,
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     MozWindowButtonBoxMaximized,
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     MozWindowButtonClose,
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     MozWindowButtonMaximize,
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     MozWindowButtonMinimize,
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     MozWindowButtonRestore,
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     MozWindowFrameBottom,
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     MozWindowFrameLeft,
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     MozWindowFrameRight,
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     MozWindowTitlebar,
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     MozWindowTitlebarMaximized,
 
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     MozGtkInfoBar,
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     MozMacActiveSourceListSelection,
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     MozMacDisclosureButtonClosed,
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     MozMacDisclosureButtonOpen,
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     MozMacSourceList,
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     MozMacSourceListSelection,
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     MozMacVibrancyDark,
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     MozMacVibrancyLight,
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     MozMacVibrantTitlebarDark,
-    #[parse(condition = "in_ua_or_chrome_sheet")]
+    #[parse(condition = "ParserContext::in_ua_or_chrome_sheet")]
     MozMacVibrantTitlebarLight,
 
     /// A non-disappearing scrollbar.

From 7b144996659a5ebfe5da263dd4b8ab10a87e0749 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Emilio=20Cobos=20=C3=81lvarez?= <emilio@crisal.io>
Date: Fri, 29 Mar 2019 11:11:27 +0000
Subject: [PATCH 05/59] style: Unship line-height: -moz-block-height.

They're only used in forms.css, and only for some anonymous content, which are
not content-accessible in the first place.

The only place where this could be exposed is calling
getComputedStyle(input, "::placeholder"), so I think this should be pretty safe,
but I've added a pref just in case.

While at it, also derive the Parse implementation. Less code is better.

Differential Revision: https://phabricator.services.mozilla.com/D25118
---
 components/style/values/generics/text.rs  | 10 +++++++++
 components/style/values/specified/text.rs | 27 -----------------------
 2 files changed, 10 insertions(+), 27 deletions(-)

diff --git a/components/style/values/generics/text.rs b/components/style/values/generics/text.rs
index 7dae932faac..509491c8624 100644
--- a/components/style/values/generics/text.rs
+++ b/components/style/values/generics/text.rs
@@ -61,6 +61,14 @@ impl<Value> Spacing<Value> {
     }
 }
 
+#[cfg(feature = "gecko")]
+fn line_height_moz_block_height_enabled(context: &ParserContext) -> bool {
+    use crate::gecko_bindings::structs;
+    context.in_ua_sheet() || unsafe {
+        structs::StaticPrefs_sVarCache_layout_css_line_height_moz_block_height_content_enabled
+    }
+}
+
 /// A generic value for the `line-height` property.
 #[derive(
     Animate,
@@ -73,6 +81,7 @@ impl<Value> Spacing<Value> {
     SpecifiedValueInfo,
     ToAnimatedValue,
     ToCss,
+    Parse,
 )]
 #[repr(C, u8)]
 pub enum GenericLineHeight<N, L> {
@@ -80,6 +89,7 @@ pub enum GenericLineHeight<N, L> {
     Normal,
     /// `-moz-block-height`
     #[cfg(feature = "gecko")]
+    #[parse(condition = "line_height_moz_block_height_enabled")]
     MozBlockHeight,
     /// `<number>`
     Number(N),
diff --git a/components/style/values/specified/text.rs b/components/style/values/specified/text.rs
index 33bda52aa9d..1c2f8499af5 100644
--- a/components/style/values/specified/text.rs
+++ b/components/style/values/specified/text.rs
@@ -73,33 +73,6 @@ impl Parse for WordSpacing {
     }
 }
 
-impl Parse for LineHeight {
-    fn parse<'i, 't>(
-        context: &ParserContext,
-        input: &mut Parser<'i, 't>,
-    ) -> Result<Self, ParseError<'i>> {
-        if let Ok(number) = input.try(|i| NonNegativeNumber::parse(context, i)) {
-            return Ok(GenericLineHeight::Number(number));
-        }
-        if let Ok(nlp) = input.try(|i| NonNegativeLengthPercentage::parse(context, i)) {
-            return Ok(GenericLineHeight::Length(nlp));
-        }
-        let location = input.current_source_location();
-        let ident = input.expect_ident()?;
-        match ident {
-            ref ident if ident.eq_ignore_ascii_case("normal") => Ok(GenericLineHeight::Normal),
-            #[cfg(feature = "gecko")]
-            ref ident if ident.eq_ignore_ascii_case("-moz-block-height") => {
-                Ok(GenericLineHeight::MozBlockHeight)
-            },
-            ident => {
-                Err(location
-                    .new_custom_error(SelectorParseErrorKind::UnexpectedIdent(ident.clone())))
-            },
-        }
-    }
-}
-
 impl ToComputedValue for LineHeight {
     type ComputedValue = ComputedLineHeight;
 

From 5ebc3f8dfadf5fb8a98f158bf144ccb734a59827 Mon Sep 17 00:00:00 2001
From: Masayuki Nakano <masayuki@d-toybox.com>
Date: Fri, 29 Mar 2019 15:12:47 +0000
Subject: [PATCH 06/59] Rename Document::GetShell() to Document::GetPresShell()
 and make it return PresShell* rather than nsIPresShell*

This makes `Document::GetShell()` return `PresShell*` instead of `nsIPresShell`.

Additonally, "shell" is unclear ("docshell" vs. "presshell").  Therefore, this
also renames `Document::GetShell()` to `Document::GetPresShell()`.

Similarly, some other method names of `Document` are also renamed from
`*Shell*` to `*PresShell*`.

Differential Revision: https://phabricator.services.mozilla.com/D25338
---
 components/style/gecko/media_queries.rs | 1 +
 1 file changed, 1 insertion(+)

diff --git a/components/style/gecko/media_queries.rs b/components/style/gecko/media_queries.rs
index 4c04d9573e5..b39e748ce2b 100644
--- a/components/style/gecko/media_queries.rs
+++ b/components/style/gecko/media_queries.rs
@@ -169,6 +169,7 @@ impl Device {
             self.document()
                 .mPresShell
                 .as_ref()?
+                ._base
                 .mPresContext
                 .mRawPtr
                 .as_ref()

From 91586eea0e1748531eb010d2f1061eb834f384e5 Mon Sep 17 00:00:00 2001
From: Cameron McCormack <cam@mcc.id.au>
Date: Sat, 30 Mar 2019 00:15:43 +0000
Subject: [PATCH 07/59] style: Allow references to static C++ URLExtraData
 objects from Rust UrlExtraData.

Each user agent style sheet has a unique URLExtraData object containing
its URL, but since they are refcounted objects, we can't share them
easily across processes.  Rather than adding support for copying them
into a shared memory buffer like we will do with the Rust objects, here
we just set up a static array of URLExtraData objects per UA style
sheet.  The array will be filled in in a later patch.

Rust UrlExtraData objects, once they are transformed into their
sharable form and copied into the shared memory buffer, will reference
them by an index.

Differential Revision: https://phabricator.services.mozilla.com/D17182
---
 components/style/stylesheets/mod.rs | 83 +++++++++++++++++++++++++----
 1 file changed, 72 insertions(+), 11 deletions(-)

diff --git a/components/style/stylesheets/mod.rs b/components/style/stylesheets/mod.rs
index 58922187db2..8e4ec499a05 100644
--- a/components/style/stylesheets/mod.rs
+++ b/components/style/stylesheets/mod.rs
@@ -23,6 +23,10 @@ mod stylesheet;
 pub mod supports_rule;
 pub mod viewport_rule;
 
+#[cfg(feature = "gecko")]
+use crate::gecko_bindings::sugar::refptr::RefCounted;
+#[cfg(feature = "gecko")]
+use crate::gecko_bindings::{bindings, structs};
 use crate::parser::ParserContext;
 use crate::shared_lock::{DeepCloneParams, DeepCloneWithLock, Locked};
 use crate::shared_lock::{SharedRwLock, SharedRwLockReadGuard, ToCssWithGuard};
@@ -32,6 +36,8 @@ use cssparser::{parse_one_rule, Parser, ParserInput};
 use malloc_size_of::{MallocSizeOfOps, MallocUnconditionalShallowSizeOf};
 use servo_arc::Arc;
 use std::fmt;
+#[cfg(feature = "gecko")]
+use std::mem;
 use style_traits::ParsingMode;
 
 pub use self::counter_style_rule::CounterStyleRule;
@@ -60,18 +66,56 @@ pub use self::viewport_rule::ViewportRule;
 pub type UrlExtraData = ::servo_url::ServoUrl;
 
 /// Extra data that the backend may need to resolve url values.
+///
+/// If the usize's lowest bit is 0, then this is a strong reference to a
+/// structs::URLExtraData object.
+///
+/// Otherwise, shifting the usize's bits the right by one gives the
+/// UserAgentStyleSheetID value corresponding to the style sheet whose
+/// URLExtraData this is, which is stored in URLExtraData_sShared.  We don't
+/// hold a strong reference to that object from here, but we rely on that
+/// array's objects being held alive until shutdown.
+///
+/// We use this packed representation rather than an enum so that
+/// `from_ptr_ref` can work.
 #[cfg(feature = "gecko")]
-#[derive(Clone, PartialEq)]
-pub struct UrlExtraData(
-    pub crate::gecko_bindings::sugar::refptr::RefPtr<crate::gecko_bindings::structs::URLExtraData>,
-);
+#[derive(PartialEq)]
+pub struct UrlExtraData(usize);
+
+#[cfg(feature = "gecko")]
+impl Clone for UrlExtraData {
+    fn clone(&self) -> UrlExtraData {
+        UrlExtraData::new(self.ptr())
+    }
+}
+
+#[cfg(feature = "gecko")]
+impl Drop for UrlExtraData {
+    fn drop(&mut self) {
+        // No need to release when we have an index into URLExtraData_sShared.
+        if self.0 & 1 == 0 {
+            unsafe {
+                self.as_ref().release();
+            }
+        }
+    }
+}
 
 #[cfg(feature = "gecko")]
 impl UrlExtraData {
+    /// Create a new UrlExtraData wrapping a pointer to the specified Gecko
+    /// URLExtraData object.
+    pub fn new(ptr: *mut structs::URLExtraData) -> UrlExtraData {
+        unsafe {
+            (*ptr).addref();
+        }
+        UrlExtraData(ptr as usize)
+    }
+
     /// True if this URL scheme is chrome.
     #[inline]
     pub fn is_chrome(&self) -> bool {
-        self.0.mIsChrome
+        self.as_ref().mIsChrome
     }
 
     /// Create a reference to this `UrlExtraData` from a reference to pointer.
@@ -80,16 +124,30 @@ impl UrlExtraData {
     ///
     /// This method doesn't touch refcount.
     #[inline]
-    pub unsafe fn from_ptr_ref(ptr: &*mut crate::gecko_bindings::structs::URLExtraData) -> &Self {
-        ::std::mem::transmute(ptr)
+    pub unsafe fn from_ptr_ref(ptr: &*mut structs::URLExtraData) -> &Self {
+        mem::transmute(ptr)
+    }
+
+    /// Returns a pointer to the Gecko URLExtraData object.
+    pub fn ptr(&self) -> *mut structs::URLExtraData {
+        if self.0 & 1 == 0 {
+            self.0 as *mut structs::URLExtraData
+        } else {
+            unsafe {
+                let sheet_id = self.0 >> 1;
+                structs::URLExtraData_sShared[sheet_id].mRawPtr
+            }
+        }
+    }
+
+    fn as_ref(&self) -> &structs::URLExtraData {
+        unsafe { &*(self.ptr() as *const structs::URLExtraData) }
     }
 }
 
 #[cfg(feature = "gecko")]
 impl fmt::Debug for UrlExtraData {
     fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
-        use crate::gecko_bindings::{bindings, structs};
-
         struct DebugURI(*mut structs::nsIURI);
         impl fmt::Debug for DebugURI {
             fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
@@ -105,10 +163,13 @@ impl fmt::Debug for UrlExtraData {
         formatter
             .debug_struct("URLExtraData")
             .field("is_chrome", &self.is_chrome())
-            .field("base", &DebugURI(self.0.mBaseURI.raw::<structs::nsIURI>()))
+            .field(
+                "base",
+                &DebugURI(self.as_ref().mBaseURI.raw::<structs::nsIURI>()),
+            )
             .field(
                 "referrer",
-                &DebugURI(self.0.mReferrer.raw::<structs::nsIURI>()),
+                &DebugURI(self.as_ref().mReferrer.raw::<structs::nsIURI>()),
             )
             .finish()
     }

From b6b5ddda71b475e4edb474982ad3b2d5df380fe4 Mon Sep 17 00:00:00 2001
From: Cameron McCormack <cam@mcc.id.au>
Date: Sat, 30 Mar 2019 00:15:51 +0000
Subject: [PATCH 08/59] style: Allow references to static, single-generic C++
 SharedFontList objects from Rust FontFamilyList.

UA style sheets only ever specify a single generic font family in font-family
properties, so we pre-create a unique, static SharedFontList for each generic
and change the representation of FontFamilyList to be able to refer to them
by their generic ID.  This avoids having to share refcounted SharedFontList
objects across processes.

Differential Revision: https://phabricator.services.mozilla.com/D17183
---
 components/style/properties/gecko.mako.rs     |  6 +-
 .../style/properties/longhands/font.mako.rs   |  6 +-
 components/style/values/computed/font.rs      | 60 ++++++++++++++-----
 components/style/values/specified/font.rs     | 10 +++-
 4 files changed, 59 insertions(+), 23 deletions(-)

diff --git a/components/style/properties/gecko.mako.rs b/components/style/properties/gecko.mako.rs
index 7c5f4a94c01..5af9f5be7c6 100644
--- a/components/style/properties/gecko.mako.rs
+++ b/components/style/properties/gecko.mako.rs
@@ -1993,7 +1993,9 @@ fn static_assert() {
         } else {
             v.families.single_generic().unwrap_or(structs::kGenericFont_NONE)
         };
-        self.gecko.mFont.fontlist.mFontlist.mBasePtr.set_move(v.families.0.clone());
+        self.gecko.mFont.fontlist.mFontlist.mBasePtr.set_move(
+            v.families.shared_font_list().clone()
+        );
         // Fixed-up if needed in Cascade::fixup_font_stuff.
         self.gecko.mFont.fontlist.mDefaultFontType = FontFamilyType::eFamily_none;
     }
@@ -2038,7 +2040,7 @@ fn static_assert() {
             };
             FontFamilyList::new(Box::new([default]))
         } else {
-            FontFamilyList(shared_fontlist)
+            FontFamilyList::SharedFontList(shared_fontlist)
         };
 
         FontFamily {
diff --git a/components/style/properties/longhands/font.mako.rs b/components/style/properties/longhands/font.mako.rs
index 88369ab9f21..466a4471608 100644
--- a/components/style/properties/longhands/font.mako.rs
+++ b/components/style/properties/longhands/font.mako.rs
@@ -406,9 +406,9 @@ ${helpers.predefined_type(
                 let font_style = FontStyle::from_gecko(system.style);
                 let ret = ComputedSystemFont {
                     font_family: FontFamily {
-                        families: FontFamilyList(unsafe {
-                            system.fontlist.mFontlist.mBasePtr.to_safe()
-                        }),
+                        families: FontFamilyList::SharedFontList(
+                            unsafe { system.fontlist.mFontlist.mBasePtr.to_safe() }
+                        ),
                         is_system_font: true,
                     },
                     font_size: FontSize {
diff --git a/components/style/values/computed/font.rs b/components/style/values/computed/font.rs
index c78eb9df2e3..8e51072d9a7 100644
--- a/components/style/values/computed/font.rs
+++ b/components/style/values/computed/font.rs
@@ -24,6 +24,8 @@ use cssparser::{serialize_identifier, CssStringWriter, Parser};
 use malloc_size_of::{MallocSizeOf, MallocSizeOfOps};
 use std::fmt::{self, Write};
 use std::hash::{Hash, Hasher};
+#[cfg(feature = "gecko")]
+use std::mem;
 #[cfg(feature = "servo")]
 use std::slice;
 use style_traits::{CssWriter, ParseError, ToCss};
@@ -202,9 +204,8 @@ impl MallocSizeOf for FontFamily {
         // SharedFontList objects are generally shared from the pointer
         // stored in the specified value. So only count this if the
         // SharedFontList is unshared.
-        unsafe {
-            bindings::Gecko_SharedFontList_SizeOfIncludingThisIfUnshared(self.families.0.get())
-        }
+        let shared_font_list = self.families.shared_font_list().get();
+        unsafe { bindings::Gecko_SharedFontList_SizeOfIncludingThisIfUnshared(shared_font_list) }
     }
 }
 
@@ -500,7 +501,12 @@ pub struct FontFamilyList(Box<[SingleFontFamily]>);
 #[cfg(feature = "gecko")]
 #[derive(Clone, Debug)]
 /// A list of SingleFontFamily
-pub struct FontFamilyList(pub RefPtr<structs::SharedFontList>);
+pub enum FontFamilyList {
+    /// A strong reference to a Gecko SharedFontList object.
+    SharedFontList(RefPtr<structs::SharedFontList>),
+    /// A font-family generic ID.
+    Generic(structs::FontFamilyType),
+}
 
 #[cfg(feature = "gecko")]
 impl Hash for FontFamilyList {
@@ -510,7 +516,7 @@ impl Hash for FontFamilyList {
     {
         use crate::string_cache::WeakAtom;
 
-        for name in self.0.mNames.iter() {
+        for name in self.shared_font_list().mNames.iter() {
             name.mType.hash(state);
             if !name.mName.mRawPtr.is_null() {
                 unsafe {
@@ -524,10 +530,13 @@ impl Hash for FontFamilyList {
 #[cfg(feature = "gecko")]
 impl PartialEq for FontFamilyList {
     fn eq(&self, other: &FontFamilyList) -> bool {
-        if self.0.mNames.len() != other.0.mNames.len() {
+        let self_list = self.shared_font_list();
+        let other_list = other.shared_font_list();
+
+        if self_list.mNames.len() != other_list.mNames.len() {
             return false;
         }
-        for (a, b) in self.0.mNames.iter().zip(other.0.mNames.iter()) {
+        for (a, b) in self_list.mNames.iter().zip(other_list.mNames.iter()) {
             if a.mType != b.mType || a.mName.mRawPtr != b.mName.mRawPtr {
                 return false;
             }
@@ -540,14 +549,14 @@ impl PartialEq for FontFamilyList {
 impl Eq for FontFamilyList {}
 
 impl FontFamilyList {
-    #[cfg(feature = "servo")]
     /// Return FontFamilyList with a vector of SingleFontFamily
+    #[cfg(feature = "servo")]
     pub fn new(families: Box<[SingleFontFamily]>) -> FontFamilyList {
         FontFamilyList(families)
     }
 
-    #[cfg(feature = "gecko")]
     /// Return FontFamilyList with a vector of SingleFontFamily
+    #[cfg(feature = "gecko")]
     pub fn new(families: Box<[SingleFontFamily]>) -> FontFamilyList {
         let fontlist;
         let names;
@@ -578,26 +587,26 @@ impl FontFamilyList {
             }
         }
 
-        FontFamilyList(unsafe { RefPtr::from_addrefed(fontlist) })
+        FontFamilyList::SharedFontList(unsafe { RefPtr::from_addrefed(fontlist) })
     }
 
-    #[cfg(feature = "servo")]
     /// Return iterator of SingleFontFamily
+    #[cfg(feature = "servo")]
     pub fn iter(&self) -> slice::Iter<SingleFontFamily> {
         self.0.iter()
     }
 
-    #[cfg(feature = "gecko")]
     /// Return iterator of SingleFontFamily
+    #[cfg(feature = "gecko")]
     pub fn iter(&self) -> FontFamilyNameIter {
         FontFamilyNameIter {
-            names: &self.0.mNames,
+            names: &self.shared_font_list().mNames,
             cur: 0,
         }
     }
 
-    #[cfg(feature = "gecko")]
     /// Return the generic ID if it is a single generic font
+    #[cfg(feature = "gecko")]
     pub fn single_generic(&self) -> Option<u8> {
         let mut iter = self.iter();
         if let Some(SingleFontFamily::Generic(ref name)) = iter.next() {
@@ -607,10 +616,29 @@ impl FontFamilyList {
         }
         None
     }
+
+    /// Return a reference to the Gecko SharedFontList.
+    #[cfg(feature = "gecko")]
+    pub fn shared_font_list(&self) -> &RefPtr<structs::SharedFontList> {
+        match self {
+            FontFamilyList::SharedFontList(r) => r,
+            FontFamilyList::Generic(t) => {
+                unsafe {
+                    // TODO(heycam): Should really add StaticRefPtr sugar.
+                    let index =
+                        (*t as usize) - (structs::FontFamilyType::eFamily_generic_first as usize);
+                    mem::transmute::<
+                        &structs::StaticRefPtr<structs::SharedFontList>,
+                        &RefPtr<structs::SharedFontList>,
+                    >(&structs::SharedFontList_sSingleGenerics[index])
+                }
+            },
+        }
+    }
 }
 
-#[cfg(feature = "gecko")]
 /// Iterator of FontFamily
+#[cfg(feature = "gecko")]
 pub struct FontFamilyNameIter<'a> {
     names: &'a structs::nsTArray<structs::FontFamilyName>,
     cur: usize,
@@ -631,8 +659,8 @@ impl<'a> Iterator for FontFamilyNameIter<'a> {
     }
 }
 
-#[derive(Animate, Clone, ComputeSquaredDistance, Copy, Debug, MallocSizeOf, PartialEq, ToCss)]
 /// Preserve the readability of text when font fallback occurs
+#[derive(Animate, Clone, ComputeSquaredDistance, Copy, Debug, MallocSizeOf, PartialEq, ToCss)]
 pub enum FontSizeAdjust {
     #[animation(error)]
     /// None variant
diff --git a/components/style/values/specified/font.rs b/components/style/values/specified/font.rs
index 6c92acbf1b9..baae46aed2f 100644
--- a/components/style/values/specified/font.rs
+++ b/components/style/values/specified/font.rs
@@ -567,8 +567,14 @@ impl MallocSizeOf for FontFamily {
         match *self {
             FontFamily::Values(ref v) => {
                 // Although a SharedFontList object is refcounted, we always
-                // attribute its size to the specified value.
-                unsafe { bindings::Gecko_SharedFontList_SizeOfIncludingThis(v.0.get()) }
+                // attribute its size to the specified value, as long as it's
+                // not a value in SharedFontList::sSingleGenerics.
+                if matches!(v, FontFamilyList::SharedFontList(_)) {
+                    let ptr = v.shared_font_list().get();
+                    unsafe { bindings::Gecko_SharedFontList_SizeOfIncludingThis(ptr) }
+                } else {
+                    0
+                }
             },
             FontFamily::System(_) => 0,
         }

From 7e7a9e2ec55a6a5a70271dcfb81d19fcdaf40c61 Mon Sep 17 00:00:00 2001
From: Cameron McCormack <cam@mcc.id.au>
Date: Sat, 30 Mar 2019 00:15:53 +0000
Subject: [PATCH 09/59] style: Allow C++ URLValue objects to be lazily created
 from Rust SpecifiedUrls.

This avoids having to support storing refcounted URLValue objects in shared memory,
which would be tricky.

Depends on D17183

Differential Revision: https://phabricator.services.mozilla.com/D17184
---
 components/style/gecko/conversions.rs     |   7 +-
 components/style/gecko/url.rs             | 139 +++++++++++++++++++---
 components/style/properties/gecko.mako.rs |   6 +-
 3 files changed, 126 insertions(+), 26 deletions(-)

diff --git a/components/style/gecko/conversions.rs b/components/style/gecko/conversions.rs
index 356636fc6bb..e36ff141eae 100644
--- a/components/style/gecko/conversions.rs
+++ b/components/style/gecko/conversions.rs
@@ -123,14 +123,11 @@ impl nsStyleImage {
         match image {
             GenericImage::Gradient(boxed_gradient) => self.set_gradient(*boxed_gradient),
             GenericImage::Url(ref url) => unsafe {
-                bindings::Gecko_SetLayerImageImageValue(self, (url.0).0.url_value.get());
+                bindings::Gecko_SetLayerImageImageValue(self, url.url_value_ptr())
             },
             GenericImage::Rect(ref image_rect) => {
                 unsafe {
-                    bindings::Gecko_SetLayerImageImageValue(
-                        self,
-                        (image_rect.url.0).0.url_value.get(),
-                    );
+                    bindings::Gecko_SetLayerImageImageValue(self, image_rect.url.url_value_ptr());
                     bindings::Gecko_InitializeImageCropRect(self);
 
                     // Set CropRect
diff --git a/components/style/gecko/url.rs b/components/style/gecko/url.rs
index df5f1137532..e5f1b32e04c 100644
--- a/components/style/gecko/url.rs
+++ b/components/style/gecko/url.rs
@@ -17,7 +17,9 @@ use cssparser::Parser;
 use malloc_size_of::{MallocSizeOf, MallocSizeOfOps};
 use nsstring::nsCString;
 use servo_arc::Arc;
+use std::collections::HashMap;
 use std::fmt::{self, Write};
+use std::sync::RwLock;
 use style_traits::{CssWriter, ParseError, ToCss};
 
 /// A CSS url() value for gecko.
@@ -81,6 +83,20 @@ impl CssUrlData {
     }
 }
 
+#[cfg(debug_assertions)]
+impl Drop for CssUrlData {
+    fn drop(&mut self) {
+        assert!(
+            !URL_VALUE_TABLE
+                .read()
+                .unwrap()
+                .contains_key(&CssUrlDataKey(self as *mut _ as *const _)),
+            "All CssUrlData objects used as keys in URL_VALUE_TABLE should be \
+             from shared memory style sheets, and so should never be dropped",
+        );
+    }
+}
+
 impl Parse for CssUrl {
     fn parse<'i, 't>(
         context: &ParserContext,
@@ -104,6 +120,24 @@ impl MallocSizeOf for CssUrl {
     }
 }
 
+/// A key type for URL_VALUE_TABLE.
+#[derive(Hash, PartialEq, Eq)]
+struct CssUrlDataKey(*const CssUrlData);
+
+unsafe impl Sync for CssUrlDataKey {}
+unsafe impl Send for CssUrlDataKey {}
+
+/// The source of a Gecko URLValue object for a SpecifiedUrl.
+#[derive(Clone, Debug)]
+pub enum URLValueSource {
+    /// A strong reference to a Gecko URLValue object.
+    URLValue(RefPtr<URLValue>),
+    /// A CORSMode value used to lazily construct a Gecko URLValue object.
+    ///
+    /// The lazily created object will be stored in URL_VALUE_TABLE.
+    CORSMode(CORSMode),
+}
+
 /// A specified non-image `url()` value.
 #[derive(Clone, Debug, SpecifiedValueInfo, ToCss)]
 pub struct SpecifiedUrl {
@@ -111,8 +145,20 @@ pub struct SpecifiedUrl {
     pub url: CssUrl,
     /// Gecko's URLValue so that we can reuse it while rematching a
     /// property with this specified value.
+    ///
+    /// Box this to avoid SpecifiedUrl getting bigger than two words,
+    /// and increasing the size of PropertyDeclaration.
     #[css(skip)]
-    pub url_value: RefPtr<URLValue>,
+    url_value: Box<URLValueSource>,
+}
+
+fn make_url_value(url: &CssUrl, cors_mode: CORSMode) -> RefPtr<URLValue> {
+    unsafe {
+        let ptr = bindings::Gecko_URLValue_Create(url.0.clone().into_strong(), cors_mode);
+        // We do not expect Gecko_URLValue_Create returns null.
+        debug_assert!(!ptr.is_null());
+        RefPtr::from_addrefed(ptr)
+    }
 }
 
 impl SpecifiedUrl {
@@ -122,12 +168,7 @@ impl SpecifiedUrl {
     }
 
     fn from_css_url_with_cors(url: CssUrl, cors: CORSMode) -> Self {
-        let url_value = unsafe {
-            let ptr = bindings::Gecko_URLValue_Create(url.0.clone().into_strong(), cors);
-            // We do not expect Gecko_URLValue_Create returns null.
-            debug_assert!(!ptr.is_null());
-            RefPtr::from_addrefed(ptr)
-        };
+        let url_value = Box::new(URLValueSource::URLValue(make_url_value(&url, cors)));
         Self { url, url_value }
     }
 
@@ -140,6 +181,45 @@ impl SpecifiedUrl {
         use crate::gecko_bindings::structs::root::mozilla::CORSMode_CORS_ANONYMOUS;
         Self::from_css_url_with_cors(url, CORSMode_CORS_ANONYMOUS)
     }
+
+    fn with_url_value<F, T>(&self, f: F) -> T
+    where
+        F: FnOnce(&RefPtr<URLValue>) -> T,
+    {
+        match *self.url_value {
+            URLValueSource::URLValue(ref r) => f(r),
+            URLValueSource::CORSMode(cors_mode) => {
+                {
+                    let guard = URL_VALUE_TABLE.read().unwrap();
+                    if let Some(r) = guard.get(&(CssUrlDataKey(&*self.url.0 as *const _))) {
+                        return f(r);
+                    }
+                }
+                let mut guard = URL_VALUE_TABLE.write().unwrap();
+                let r = guard
+                    .entry(CssUrlDataKey(&*self.url.0 as *const _))
+                    .or_insert_with(|| make_url_value(&self.url, cors_mode));
+                f(r)
+            },
+        }
+    }
+
+    /// Clone a new, strong reference to the Gecko URLValue.
+    pub fn clone_url_value(&self) -> RefPtr<URLValue> {
+        self.with_url_value(RefPtr::clone)
+    }
+
+    /// Get a raw pointer to the URLValue held by this SpecifiedUrl, for FFI.
+    pub fn url_value_ptr(&self) -> *mut URLValue {
+        self.with_url_value(RefPtr::get)
+    }
+}
+
+/// Clears URL_VALUE_TABLE.  Entries in this table, which are for specified URL
+/// values that come from shared memory style sheets, would otherwise persist
+/// until the end of the process and be reported as leaks.
+pub fn shutdown() {
+    URL_VALUE_TABLE.write().unwrap().clear();
 }
 
 impl Parse for SpecifiedUrl {
@@ -165,7 +245,7 @@ impl MallocSizeOf for SpecifiedUrl {
         // Although this is a RefPtr, this is the primary reference because
         // SpecifiedUrl is responsible for creating the url_value. So we
         // measure unconditionally here.
-        n += unsafe { bindings::Gecko_URLValue_SizeOfIncludingThis(self.url_value.get()) };
+        n += unsafe { bindings::Gecko_URLValue_SizeOfIncludingThis(self.url_value_ptr()) };
         n
     }
 }
@@ -258,7 +338,8 @@ impl ToCss for ComputedUrl {
     where
         W: Write,
     {
-        serialize_computed_url(&self.0.url_value, dest, bindings::Gecko_GetComputedURLSpec)
+        self.0
+            .with_url_value(|r| serialize_computed_url(r, dest, bindings::Gecko_GetComputedURLSpec))
     }
 }
 
@@ -267,12 +348,20 @@ impl ComputedUrl {
     pub unsafe fn from_url_value(url_value: RefPtr<URLValue>) -> Self {
         let css_url = &*url_value.mCssUrl.mRawPtr;
         let url = CssUrl(CssUrlData::as_arc(&css_url).clone_arc());
-        ComputedUrl(SpecifiedUrl { url, url_value })
+        ComputedUrl(SpecifiedUrl {
+            url,
+            url_value: Box::new(URLValueSource::URLValue(url_value)),
+        })
+    }
+
+    /// Clone a new, strong reference to the Gecko URLValue.
+    pub fn clone_url_value(&self) -> RefPtr<URLValue> {
+        self.0.clone_url_value()
     }
 
     /// Get a raw pointer to the URLValue held by this ComputedUrl, for FFI.
     pub fn url_value_ptr(&self) -> *mut URLValue {
-        self.0.url_value.get()
+        self.0.url_value_ptr()
     }
 }
 
@@ -285,11 +374,9 @@ impl ToCss for ComputedImageUrl {
     where
         W: Write,
     {
-        serialize_computed_url(
-            &(self.0).0.url_value,
-            dest,
-            bindings::Gecko_GetComputedImageURLSpec,
-        )
+        (self.0).0.with_url_value(|r| {
+            serialize_computed_url(r, dest, bindings::Gecko_GetComputedImageURLSpec)
+        })
     }
 }
 
@@ -299,11 +386,27 @@ impl ComputedImageUrl {
         let url_value = image_request.mImageValue.to_safe();
         let css_url = &*url_value.mCssUrl.mRawPtr;
         let url = CssUrl(CssUrlData::as_arc(&css_url).clone_arc());
-        ComputedImageUrl(SpecifiedImageUrl(SpecifiedUrl { url, url_value }))
+        ComputedImageUrl(SpecifiedImageUrl(SpecifiedUrl {
+            url,
+            url_value: Box::new(URLValueSource::URLValue(url_value)),
+        }))
+    }
+
+    /// Clone a new, strong reference to the Gecko URLValue.
+    pub fn clone_url_value(&self) -> RefPtr<URLValue> {
+        (self.0).0.clone_url_value()
     }
 
     /// Get a raw pointer to the URLValue held by this ComputedImageUrl, for FFI.
     pub fn url_value_ptr(&self) -> *mut URLValue {
-        (self.0).0.url_value.get()
+        (self.0).0.url_value_ptr()
     }
 }
+
+lazy_static! {
+    /// A table mapping CssUrlData objects to their lazily created Gecko
+    /// URLValue objects.
+    static ref URL_VALUE_TABLE: RwLock<HashMap<CssUrlDataKey, RefPtr<URLValue>>> = {
+        Default::default()
+    };
+}
diff --git a/components/style/properties/gecko.mako.rs b/components/style/properties/gecko.mako.rs
index 5af9f5be7c6..17f10cd4552 100644
--- a/components/style/properties/gecko.mako.rs
+++ b/components/style/properties/gecko.mako.rs
@@ -826,7 +826,7 @@ def set_gecko_property(ffi_name, expr):
     pub fn set_${ident}(&mut self, v: longhands::${ident}::computed_value::T) {
         match v {
             UrlOrNone::Url(ref url) => {
-                self.gecko.${gecko_ffi_name}.set_move(url.0.url_value.clone())
+                self.gecko.${gecko_ffi_name}.set_move(url.clone_url_value())
             }
             UrlOrNone::None => {
                 unsafe {
@@ -3783,7 +3783,7 @@ fn static_assert() {
                 },
                 Url(ref url) => {
                     unsafe {
-                        bindings::Gecko_nsStyleFilter_SetURLValue(gecko_filter, url.0.url_value.get());
+                        bindings::Gecko_nsStyleFilter_SetURLValue(gecko_filter, url.url_value_ptr());
                     }
                 },
             }
@@ -4164,7 +4164,7 @@ fn set_style_svg_path(
             % if ident == "clip_path":
             ShapeSource::ImageOrUrl(ref url) => {
                 unsafe {
-                    bindings::Gecko_StyleShapeSource_SetURLValue(${ident}, url.0.url_value.get())
+                    bindings::Gecko_StyleShapeSource_SetURLValue(${ident}, url.url_value_ptr())
                 }
             }
             % elif ident == "shape_outside":

From b71a601a36c3f52a8618027b9f817ff5524af38a Mon Sep 17 00:00:00 2001
From: Cameron McCormack <cam@mcc.id.au>
Date: Sat, 30 Mar 2019 00:15:55 +0000
Subject: [PATCH 10/59] style: Add support for read only SharedRwLocks, which
 don't need any locking.

Differential Revision: https://phabricator.services.mozilla.com/D17185
---
 components/style/shared_lock.rs | 59 ++++++++++++++++++++++++++-------
 1 file changed, 47 insertions(+), 12 deletions(-)

diff --git a/components/style/shared_lock.rs b/components/style/shared_lock.rs
index 09bfa163503..f708ec58a23 100644
--- a/components/style/shared_lock.rs
+++ b/components/style/shared_lock.rs
@@ -28,6 +28,10 @@ use std::ptr;
 /// Servo needs the blocking behavior for its unsynchronized animation setup,
 /// but that may not be web-compatible and may need to be changed (at which
 /// point Servo could use AtomicRefCell too).
+///
+/// Gecko also needs the ability to have "read only" SharedRwLocks, which are
+/// used for objects stored in (read only) shared memory. Attempting to acquire
+/// write access to objects protected by a read only SharedRwLock will panic.
 #[derive(Clone)]
 #[cfg_attr(feature = "servo", derive(MallocSizeOf))]
 pub struct SharedRwLock {
@@ -36,7 +40,7 @@ pub struct SharedRwLock {
     arc: Arc<RwLock<()>>,
 
     #[cfg(feature = "gecko")]
-    cell: Arc<AtomicRefCell<SomethingZeroSizedButTyped>>,
+    cell: Option<Arc<AtomicRefCell<SomethingZeroSizedButTyped>>>,
 }
 
 #[cfg(feature = "gecko")]
@@ -61,10 +65,16 @@ impl SharedRwLock {
     #[cfg(feature = "gecko")]
     pub fn new() -> Self {
         SharedRwLock {
-            cell: Arc::new(AtomicRefCell::new(SomethingZeroSizedButTyped)),
+            cell: Some(Arc::new(AtomicRefCell::new(SomethingZeroSizedButTyped))),
         }
     }
 
+    /// Create a new read-only shared lock (gecko).
+    #[cfg(feature = "gecko")]
+    pub fn read_only() -> Self {
+        SharedRwLock { cell: None }
+    }
+
     /// Wrap the given data to make its access protected by this lock.
     pub fn wrap<T>(&self, data: T) -> Locked<T> {
         Locked {
@@ -83,7 +93,7 @@ impl SharedRwLock {
     /// Obtain the lock for reading (gecko).
     #[cfg(feature = "gecko")]
     pub fn read(&self) -> SharedRwLockReadGuard {
-        SharedRwLockReadGuard(self.cell.borrow())
+        SharedRwLockReadGuard(self.cell.as_ref().map(|cell| cell.borrow()))
     }
 
     /// Obtain the lock for writing (servo).
@@ -96,22 +106,26 @@ impl SharedRwLock {
     /// Obtain the lock for writing (gecko).
     #[cfg(feature = "gecko")]
     pub fn write(&self) -> SharedRwLockWriteGuard {
-        SharedRwLockWriteGuard(self.cell.borrow_mut())
+        SharedRwLockWriteGuard(self.cell.as_ref().unwrap().borrow_mut())
     }
 }
 
 /// Proof that a shared lock was obtained for reading (servo).
 #[cfg(feature = "servo")]
 pub struct SharedRwLockReadGuard<'a>(&'a SharedRwLock);
-/// Proof that a shared lock was obtained for writing (gecko).
+/// Proof that a shared lock was obtained for reading (gecko).
 #[cfg(feature = "gecko")]
-pub struct SharedRwLockReadGuard<'a>(AtomicRef<'a, SomethingZeroSizedButTyped>);
+pub struct SharedRwLockReadGuard<'a>(Option<AtomicRef<'a, SomethingZeroSizedButTyped>>);
 #[cfg(feature = "servo")]
 impl<'a> Drop for SharedRwLockReadGuard<'a> {
     fn drop(&mut self) {
         // Unsafe: self.lock is private to this module, only ever set after `read()`,
         // and never copied or cloned (see `compile_time_assert` below).
-        unsafe { self.0.arc.force_unlock_read() }
+        if let Some(arc) = self.0.arc {
+            unsafe {
+                arc.force_unlock_read();
+            }
+        }
     }
 }
 
@@ -149,20 +163,41 @@ impl<T: fmt::Debug> fmt::Debug for Locked<T> {
 }
 
 impl<T> Locked<T> {
+    #[cfg(feature = "servo")]
+    #[inline]
+    fn is_read_only_lock(&self) -> bool {
+        false
+    }
+
+    #[cfg(feature = "gecko")]
+    #[inline]
+    fn is_read_only_lock(&self) -> bool {
+        self.shared_lock.cell.is_none()
+    }
+
     #[cfg(feature = "servo")]
     fn same_lock_as(&self, lock: &SharedRwLock) -> bool {
         Arc::ptr_eq(&self.shared_lock.arc, &lock.arc)
     }
 
     #[cfg(feature = "gecko")]
-    fn same_lock_as(&self, derefed_guard: &SomethingZeroSizedButTyped) -> bool {
-        ptr::eq(self.shared_lock.cell.as_ptr(), derefed_guard)
+    fn same_lock_as(&self, derefed_guard: Option<&SomethingZeroSizedButTyped>) -> bool {
+        ptr::eq(
+            self.shared_lock
+                .cell
+                .as_ref()
+                .map(|cell| cell.as_ptr())
+                .unwrap_or(ptr::null_mut()),
+            derefed_guard
+                .map(|guard| guard as *const _ as *mut _)
+                .unwrap_or(ptr::null_mut()),
+        )
     }
 
     /// Access the data for reading.
     pub fn read_with<'a>(&'a self, guard: &'a SharedRwLockReadGuard) -> &'a T {
         assert!(
-            self.same_lock_as(&guard.0),
+            self.is_read_only_lock() || self.same_lock_as(guard.0.as_ref().map(|r| &**r)),
             "Locked::read_with called with a guard from an unrelated SharedRwLock"
         );
         let ptr = self.data.get();
@@ -186,8 +221,8 @@ impl<T> Locked<T> {
     /// Access the data for writing.
     pub fn write_with<'a>(&'a self, guard: &'a mut SharedRwLockWriteGuard) -> &'a mut T {
         assert!(
-            self.same_lock_as(&guard.0),
-            "Locked::write_with called with a guard from an unrelated SharedRwLock"
+            !self.is_read_only_lock() && self.same_lock_as(Some(&guard.0)),
+            "Locked::write_with called with a guard from a read only or unrelated SharedRwLock"
         );
         let ptr = self.data.get();
 

From f889b303dab662e8041584a1aca4782cc8289e94 Mon Sep 17 00:00:00 2001
From: Cameron McCormack <cam@mcc.id.au>
Date: Sat, 30 Mar 2019 00:15:57 +0000
Subject: [PATCH 11/59] style: Add support for static references to
 servo_arc::Arc. r=emilio

Differential Revision: https://phabricator.services.mozilla.com/D17186
---
 components/servo_arc/lib.rs | 192 +++++++++++++++++++++++++++++-------
 components/style/stylist.rs |   3 +
 2 files changed, 158 insertions(+), 37 deletions(-)

diff --git a/components/servo_arc/lib.rs b/components/servo_arc/lib.rs
index a18c63a1e5a..f4a929e23f8 100644
--- a/components/servo_arc/lib.rs
+++ b/components/servo_arc/lib.rs
@@ -16,6 +16,8 @@
 //! * We can add methods to support our custom use cases [1].
 //! * We have support for dynamically-sized types (see from_header_and_iter).
 //! * We have support for thin arcs to unsized types (see ThinArc).
+//! * We have support for references to static data, which don't do any
+//!   refcounting.
 //!
 //! [1]: https://bugzilla.mozilla.org/show_bug.cgi?id=1360883
 
@@ -32,6 +34,7 @@ use nodrop::NoDrop;
 #[cfg(feature = "servo")]
 use serde::{Deserialize, Serialize};
 use stable_deref_trait::{CloneStableDeref, StableDeref};
+use std::alloc::Layout;
 use std::borrow;
 use std::cmp::Ordering;
 use std::convert::From;
@@ -74,6 +77,10 @@ macro_rules! offset_of {
 /// necessarily) at _exactly_ `MAX_REFCOUNT + 1` references.
 const MAX_REFCOUNT: usize = (isize::MAX) as usize;
 
+/// Special refcount value that means the data is not reference counted,
+/// and that the `Arc` is really acting as a read-only static reference.
+const STATIC_REFCOUNT: usize = usize::MAX;
+
 /// An atomically reference counted shared pointer
 ///
 /// See the documentation for [`Arc`] in the standard library. Unlike the
@@ -194,6 +201,32 @@ impl<T> Arc<T> {
         }
     }
 
+    /// Create a new static Arc<T> (one that won't reference count the object)
+    /// and place it in the allocation provided by the specified `alloc`
+    /// function.
+    ///
+    /// `alloc` must return a pointer into a static allocation suitable for
+    /// storing data with the `Layout` passed into it. The pointer returned by
+    /// `alloc` will not be freed.
+    #[inline]
+    pub unsafe fn new_static<F>(alloc: F, data: T) -> Arc<T>
+    where
+        F: FnOnce(Layout) -> *mut u8,
+    {
+        let ptr = alloc(Layout::new::<ArcInner<T>>()) as *mut ArcInner<T>;
+
+        let x = ArcInner {
+            count: atomic::AtomicUsize::new(STATIC_REFCOUNT),
+            data,
+        };
+
+        ptr::write(ptr, x);
+
+        Arc {
+            p: ptr::NonNull::new_unchecked(ptr),
+        }
+    }
+
     /// Produce a pointer to the data that can be converted back
     /// to an Arc. This is basically an `&Arc<T>`, without the extra indirection.
     /// It has the benefits of an `&T` but also knows about the underlying refcount
@@ -225,8 +258,14 @@ impl<T> Arc<T> {
 
     /// Returns the address on the heap of the Arc itself -- not the T within it -- for memory
     /// reporting.
+    ///
+    /// If this is a static reference, this returns null.
     pub fn heap_ptr(&self) -> *const c_void {
-        self.p.as_ptr() as *const ArcInner<T> as *const c_void
+        if self.inner().count.load(Relaxed) == STATIC_REFCOUNT {
+            ptr::null()
+        } else {
+            self.p.as_ptr() as *const ArcInner<T> as *const c_void
+        }
     }
 }
 
@@ -262,30 +301,34 @@ impl<T: ?Sized> Arc<T> {
 impl<T: ?Sized> Clone for Arc<T> {
     #[inline]
     fn clone(&self) -> Self {
-        // Using a relaxed ordering is alright here, as knowledge of the
-        // original reference prevents other threads from erroneously deleting
-        // the object.
-        //
-        // As explained in the [Boost documentation][1], Increasing the
-        // reference counter can always be done with memory_order_relaxed: New
-        // references to an object can only be formed from an existing
-        // reference, and passing an existing reference from one thread to
-        // another must already provide any required synchronization.
-        //
-        // [1]: (www.boost.org/doc/libs/1_55_0/doc/html/atomic/usage_examples.html)
-        let old_size = self.inner().count.fetch_add(1, Relaxed);
+        // Using a relaxed ordering to check for STATIC_REFCOUNT is safe, since
+        // `count` never changes between STATIC_REFCOUNT and other values.
+        if self.inner().count.load(Relaxed) != STATIC_REFCOUNT {
+            // Using a relaxed ordering is alright here, as knowledge of the
+            // original reference prevents other threads from erroneously deleting
+            // the object.
+            //
+            // As explained in the [Boost documentation][1], Increasing the
+            // reference counter can always be done with memory_order_relaxed: New
+            // references to an object can only be formed from an existing
+            // reference, and passing an existing reference from one thread to
+            // another must already provide any required synchronization.
+            //
+            // [1]: (www.boost.org/doc/libs/1_55_0/doc/html/atomic/usage_examples.html)
+            let old_size = self.inner().count.fetch_add(1, Relaxed);
 
-        // However we need to guard against massive refcounts in case someone
-        // is `mem::forget`ing Arcs. If we don't do this the count can overflow
-        // and users will use-after free. We racily saturate to `isize::MAX` on
-        // the assumption that there aren't ~2 billion threads incrementing
-        // the reference count at once. This branch will never be taken in
-        // any realistic program.
-        //
-        // We abort because such a program is incredibly degenerate, and we
-        // don't care to support it.
-        if old_size > MAX_REFCOUNT {
-            process::abort();
+            // However we need to guard against massive refcounts in case someone
+            // is `mem::forget`ing Arcs. If we don't do this the count can overflow
+            // and users will use-after free. We racily saturate to `isize::MAX` on
+            // the assumption that there aren't ~2 billion threads incrementing
+            // the reference count at once. This branch will never be taken in
+            // any realistic program.
+            //
+            // We abort because such a program is incredibly degenerate, and we
+            // don't care to support it.
+            if old_size > MAX_REFCOUNT {
+                process::abort();
+            }
         }
 
         unsafe {
@@ -351,7 +394,8 @@ impl<T: ?Sized> Arc<T> {
         }
     }
 
-    /// Whether or not the `Arc` is uniquely owned (is the refcount 1?)
+    /// Whether or not the `Arc` is uniquely owned (is the refcount 1?) and not
+    /// a static reference.
     #[inline]
     pub fn is_unique(&self) -> bool {
         // See the extensive discussion in [1] for why this needs to be Acquire.
@@ -364,6 +408,12 @@ impl<T: ?Sized> Arc<T> {
 impl<T: ?Sized> Drop for Arc<T> {
     #[inline]
     fn drop(&mut self) {
+        // Using a relaxed ordering to check for STATIC_REFCOUNT is safe, since
+        // `count` never changes between STATIC_REFCOUNT and other values.
+        if self.inner().count.load(Relaxed) == STATIC_REFCOUNT {
+            return;
+        }
+
         // Because `fetch_sub` is already atomic, we do not need to synchronize
         // with other threads unless we are going to delete the object.
         if self.inner().count.fetch_sub(1, Release) != 1 {
@@ -528,10 +578,20 @@ fn divide_rounding_up(dividend: usize, divisor: usize) -> usize {
 
 impl<H, T> Arc<HeaderSlice<H, [T]>> {
     /// Creates an Arc for a HeaderSlice using the given header struct and
-    /// iterator to generate the slice. The resulting Arc will be fat.
+    /// iterator to generate the slice.
+    ///
+    /// `is_static` indicates whether to create a static Arc.
+    ///
+    /// `alloc` is used to get a pointer to the memory into which the
+    /// dynamically sized ArcInner<HeaderSlice<H, T>> value will be
+    /// written.  If `is_static` is true, then `alloc` must return a
+    /// pointer into some static memory allocation.  If it is false,
+    /// then `alloc` must return an allocation that can be dellocated
+    /// by calling Box::from_raw::<ArcInner<HeaderSlice<H, T>>> on it.
     #[inline]
-    pub fn from_header_and_iter<I>(header: H, mut items: I) -> Self
+    fn from_header_and_iter_alloc<F, I>(alloc: F, header: H, mut items: I, is_static: bool) -> Self
     where
+        F: FnOnce(Layout) -> *mut u8,
         I: Iterator<Item = T> + ExactSizeIterator,
     {
         use std::mem::size_of;
@@ -565,22 +625,20 @@ impl<H, T> Arc<HeaderSlice<H, [T]>> {
 
         let ptr: *mut ArcInner<HeaderSlice<H, [T]>>;
         unsafe {
-            // Allocate the buffer. We use Vec because the underlying allocation
-            // machinery isn't available in stable Rust.
-            //
-            // To avoid alignment issues, we allocate words rather than bytes,
-            // rounding up to the nearest word size.
-            let buffer = if mem::align_of::<T>() <= mem::align_of::<usize>() {
-                Self::allocate_buffer::<usize>(size)
+            // Allocate the buffer.
+            let layout = if mem::align_of::<T>() <= mem::align_of::<usize>() {
+                Layout::from_size_align_unchecked(size, mem::align_of::<usize>())
             } else if mem::align_of::<T>() <= mem::align_of::<u64>() {
                 // On 32-bit platforms <T> may have 8 byte alignment while usize has 4 byte aligment.
                 // Use u64 to avoid over-alignment.
                 // This branch will compile away in optimized builds.
-                Self::allocate_buffer::<u64>(size)
+                Layout::from_size_align_unchecked(size, mem::align_of::<u64>())
             } else {
                 panic!("Over-aligned type not handled");
             };
 
+            let buffer = alloc(layout);
+
             // Synthesize the fat pointer. We do this by claiming we have a direct
             // pointer to a [T], and then changing the type of the borrow. The key
             // point here is that the length portion of the fat pointer applies
@@ -594,7 +652,12 @@ impl<H, T> Arc<HeaderSlice<H, [T]>> {
             //
             // Note that any panics here (i.e. from the iterator) are safe, since
             // we'll just leak the uninitialized memory.
-            ptr::write(&mut ((*ptr).count), atomic::AtomicUsize::new(1));
+            let count = if is_static {
+                atomic::AtomicUsize::new(STATIC_REFCOUNT)
+            } else {
+                atomic::AtomicUsize::new(1)
+            };
+            ptr::write(&mut ((*ptr).count), count);
             ptr::write(&mut ((*ptr).data.header), header);
             let mut current: *mut T = &mut (*ptr).data.slice[0];
             for _ in 0..num_items {
@@ -628,8 +691,37 @@ impl<H, T> Arc<HeaderSlice<H, [T]>> {
         }
     }
 
+    /// Creates an Arc for a HeaderSlice using the given header struct and
+    /// iterator to generate the slice. The resulting Arc will be fat.
+    #[inline]
+    pub fn from_header_and_iter<I>(header: H, items: I) -> Self
+    where
+        I: Iterator<Item = T> + ExactSizeIterator,
+    {
+        Arc::from_header_and_iter_alloc(
+            |layout| {
+                // align will only ever be align_of::<usize>() or align_of::<u64>()
+                let align = layout.align();
+                unsafe {
+                    if align == mem::align_of::<usize>() {
+                        Self::allocate_buffer::<usize>(layout.size())
+                    } else {
+                        assert_eq!(align, mem::align_of::<u64>());
+                        Self::allocate_buffer::<u64>(layout.size())
+                    }
+                }
+            },
+            header,
+            items,
+            /* is_static = */ false,
+        )
+    }
+
     #[inline]
     unsafe fn allocate_buffer<W>(size: usize) -> *mut u8 {
+        // We use Vec because the underlying allocation machinery isn't
+        // available in stable Rust. To avoid alignment issues, we allocate
+        // words rather than bytes, rounding up to the nearest word size.
         let words_to_allocate = divide_rounding_up(size, mem::size_of::<W>());
         let mut vec = Vec::<W>::with_capacity(words_to_allocate);
         vec.set_len(words_to_allocate);
@@ -730,11 +822,37 @@ impl<H, T> ThinArc<H, T> {
         Arc::into_thin(Arc::from_header_and_iter(header, items))
     }
 
+    /// Create a static `ThinArc` for a HeaderSlice using the given header
+    /// struct and iterator to generate the slice, placing it in the allocation
+    /// provided by the specified `alloc` function.
+    ///
+    /// `alloc` must return a pointer into a static allocation suitable for
+    /// storing data with the `Layout` passed into it. The pointer returned by
+    /// `alloc` will not be freed.
+    pub unsafe fn static_from_header_and_iter<F, I>(alloc: F, header: H, items: I) -> Self
+    where
+        F: FnOnce(Layout) -> *mut u8,
+        I: Iterator<Item = T> + ExactSizeIterator,
+    {
+        let header = HeaderWithLength::new(header, items.len());
+        Arc::into_thin(Arc::from_header_and_iter_alloc(
+            alloc, header, items, /* is_static = */ true,
+        ))
+    }
+
     /// Returns the address on the heap of the ThinArc itself -- not the T
     /// within it -- for memory reporting.
+    ///
+    /// If this is a static ThinArc, this returns null.
     #[inline]
     pub fn heap_ptr(&self) -> *const c_void {
-        self.ptr as *const ArcInner<T> as *const c_void
+        let is_static =
+            ThinArc::with_arc(self, |a| a.inner().count.load(Relaxed) == STATIC_REFCOUNT);
+        if is_static {
+            ptr::null()
+        } else {
+            self.ptr as *const ArcInner<T> as *const c_void
+        }
     }
 }
 
diff --git a/components/style/stylist.rs b/components/style/stylist.rs
index 982440004ec..ece14e9896f 100644
--- a/components/style/stylist.rs
+++ b/components/style/stylist.rs
@@ -129,6 +129,9 @@ impl UserAgentCascadeDataCache {
     }
 
     fn expire_unused(&mut self) {
+        // is_unique() returns false for static references, but we never have
+        // static references to UserAgentCascadeDatas.  If we did, it may not
+        // make sense to put them in the cache in the first place.
         self.entries.retain(|e| !e.is_unique())
     }
 

From f581d2afb24db552afb54fa85996fdb571a13e7c Mon Sep 17 00:00:00 2001
From: Cameron McCormack <cam@mcc.id.au>
Date: Sat, 30 Mar 2019 00:15:59 +0000
Subject: [PATCH 12/59] style: Add SharedMemoryBuilder type and ToShmem trait.

Differential Revision: https://phabricator.services.mozilla.com/D17187
---
 components/style/Cargo.toml    |   1 +
 components/style/lib.rs        |   1 +
 components/to_shmem/Cargo.toml |  16 +++
 components/to_shmem/lib.rs     | 175 +++++++++++++++++++++++++++++++++
 4 files changed, 193 insertions(+)
 create mode 100644 components/to_shmem/Cargo.toml
 create mode 100644 components/to_shmem/lib.rs

diff --git a/components/style/Cargo.toml b/components/style/Cargo.toml
index 86aaa8079a4..c0dbc02a186 100644
--- a/components/style/Cargo.toml
+++ b/components/style/Cargo.toml
@@ -68,6 +68,7 @@ style_derive = {path = "../style_derive"}
 style_traits = {path = "../style_traits"}
 servo_url = {path = "../url", optional = true}
 thin-slice = "0.1.0"
+to_shmem = {path = "../to_shmem"}
 time = "0.1"
 uluru = "0.3"
 unicode-bidi = "0.3"
diff --git a/components/style/lib.rs b/components/style/lib.rs
index 37b464afb47..294b8634d56 100644
--- a/components/style/lib.rs
+++ b/components/style/lib.rs
@@ -99,6 +99,7 @@ extern crate style_traits;
 #[cfg(feature = "gecko")]
 extern crate thin_slice;
 extern crate time;
+extern crate to_shmem;
 extern crate uluru;
 extern crate unicode_bidi;
 #[allow(unused_extern_crates)]
diff --git a/components/to_shmem/Cargo.toml b/components/to_shmem/Cargo.toml
new file mode 100644
index 00000000000..666011d498f
--- /dev/null
+++ b/components/to_shmem/Cargo.toml
@@ -0,0 +1,16 @@
+[package]
+name = "to_shmem"
+version = "0.0.1"
+authors = ["The Servo Project Developers"]
+license = "MPL-2.0"
+publish = false
+
+[lib]
+name = "to_shmem"
+path = "lib.rs"
+
+[features]
+servo = []
+gecko = []
+
+[dependencies]
diff --git a/components/to_shmem/lib.rs b/components/to_shmem/lib.rs
new file mode 100644
index 00000000000..36b1353d08a
--- /dev/null
+++ b/components/to_shmem/lib.rs
@@ -0,0 +1,175 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+//! Trait for cloning data into a shared memory buffer.
+//!
+//! This module contains the SharedMemoryBuilder type and ToShmem trait.
+//!
+//! We put them here (and not in style_traits) so that we can derive ToShmem
+//! from the selectors and style crates.
+
+#![crate_name = "to_shmem"]
+#![crate_type = "rlib"]
+
+use std::alloc::Layout;
+#[cfg(debug_assertions)]
+use std::any::TypeId;
+use std::isize;
+#[cfg(debug_assertions)]
+use std::collections::HashSet;
+use std::mem::{self, ManuallyDrop};
+#[cfg(debug_assertions)]
+use std::os::raw::c_void;
+use std::ptr::{self, NonNull};
+
+// Various pointer arithmetic functions in this file can be replaced with
+// functions on `Layout` once they have stabilized:
+//
+// https://github.com/rust-lang/rust/issues/55724
+
+/// A builder object that transforms and copies values into a fixed size buffer.
+pub struct SharedMemoryBuilder {
+    /// The buffer into which values will be copied.
+    buffer: *mut u8,
+    /// The size of the buffer.
+    capacity: usize,
+    /// The current position in the buffer, where the next value will be written
+    /// at.
+    index: usize,
+    /// Pointers to every sharable value that we store in the shared memory
+    /// buffer.  We use this to assert against encountering the same value
+    /// twice, e.g. through another Arc reference, so that we don't
+    /// inadvertently store duplicate copies of values.
+    #[cfg(debug_assertions)]
+    shared_values: HashSet<*const c_void>,
+    /// Types of values that we may duplicate in the shared memory buffer when
+    /// there are shared references to them, such as in Arcs.
+    #[cfg(debug_assertions)]
+    allowed_duplication_types: HashSet<TypeId>,
+}
+
+/// Amount of padding needed after `size` bytes to ensure that the following
+/// address will satisfy `align`.
+fn padding_needed_for(size: usize, align: usize) -> usize {
+    padded_size(size, align).wrapping_sub(size)
+}
+
+/// Rounds up `size` so that the following address will satisfy `align`.
+fn padded_size(size: usize, align: usize) -> usize {
+    size.wrapping_add(align).wrapping_sub(1) & !align.wrapping_sub(1)
+}
+
+impl SharedMemoryBuilder {
+    /// Creates a new SharedMemoryBuilder using the specified buffer.
+    pub unsafe fn new(buffer: *mut u8, capacity: usize) -> SharedMemoryBuilder {
+        SharedMemoryBuilder {
+            buffer,
+            capacity,
+            index: 0,
+            #[cfg(debug_assertions)]
+            shared_values: HashSet::new(),
+            #[cfg(debug_assertions)]
+            allowed_duplication_types: HashSet::new(),
+        }
+    }
+
+    /// Notes a type as being allowed for duplication when being copied to the
+    /// shared memory buffer, such as Arcs referencing the same value.
+    #[inline]
+    pub fn add_allowed_duplication_type<T: 'static>(&mut self) {
+        #[cfg(debug_assertions)]
+        self.allowed_duplication_types.insert(TypeId::of::<T>());
+    }
+
+    /// Returns the number of bytes currently used in the buffer.
+    #[inline]
+    pub fn len(&self) -> usize {
+        self.index
+    }
+
+    /// Writes a value into the shared memory buffer and returns a pointer to
+    /// it in the buffer.
+    ///
+    /// The value is cloned and converted into a form suitable for placing into
+    /// a shared memory buffer by calling ToShmem::to_shmem on it.
+    ///
+    /// Panics if there is insufficient space in the buffer.
+    pub fn write<T: ToShmem>(&mut self, value: &T) -> *mut T {
+        // Reserve space for the value.
+        let dest: *mut T = self.alloc_value();
+
+        // Make a clone of the value with all of its heap allocations
+        // placed in the shared memory buffer.
+        let value = value.to_shmem(self);
+
+        unsafe {
+            // Copy the value into the buffer.
+            ptr::write(dest, ManuallyDrop::into_inner(value));
+        }
+
+        // Return a pointer to the shared value.
+        dest
+    }
+
+    /// Reserves space in the shared memory buffer to fit a value of type T,
+    /// and returns a pointer to that reserved space.
+    ///
+    /// Panics if there is insufficient space in the buffer.
+    pub fn alloc_value<T>(&mut self) -> *mut T {
+        self.alloc(Layout::new::<T>())
+    }
+
+    /// Reserves space in the shared memory buffer to fit an array of values of
+    /// type T, and returns a pointer to that reserved space.
+    ///
+    /// Panics if there is insufficient space in the buffer.
+    pub fn alloc_array<T>(&mut self, len: usize) -> *mut T {
+        if len == 0 {
+            return NonNull::dangling().as_ptr();
+        }
+
+        let size = mem::size_of::<T>();
+        let align = mem::align_of::<T>();
+
+        self.alloc(Layout::from_size_align(padded_size(size, align) * len, align).unwrap())
+    }
+
+    /// Reserves space in the shared memory buffer that conforms to the
+    /// specified layout, and returns a pointer to that reserved space.
+    ///
+    /// Panics if there is insufficient space in the buffer.
+    pub fn alloc<T>(&mut self, layout: Layout) -> *mut T {
+        // Amount of padding to align the value.
+        //
+        // The addition can't overflow, since self.index <= self.capacity, and
+        // for us to have successfully allocated the buffer, `buffer + capacity`
+        // can't overflow.
+        let padding = padding_needed_for(self.buffer as usize + self.index, layout.align());
+
+        // Reserve space for the padding.
+        let start = self.index.checked_add(padding).unwrap();
+        assert!(start <= std::isize::MAX as usize);  // for the cast below
+
+        // Reserve space for the value.
+        let end = start.checked_add(layout.size()).unwrap();
+        assert!(end <= self.capacity);
+
+        self.index = end;
+        unsafe { self.buffer.offset(start as isize) as *mut T }
+    }
+}
+
+/// A type that can be copied into a SharedMemoryBuilder.
+pub trait ToShmem: Sized {
+    /// Clones this value into a form suitable for writing into a
+    /// SharedMemoryBuilder.
+    ///
+    /// If this value owns any heap allocations, they should be written into
+    /// `builder` so that the return value of this function can point to the
+    /// copy in the shared memory buffer.
+    ///
+    /// The return type is wrapped in ManuallyDrop to make it harder to
+    /// accidentally invoke the destructor of the value that is produced.
+    fn to_shmem(&self, builder: &mut SharedMemoryBuilder) -> ManuallyDrop<Self>;
+}

From d8a758272e2d313025bc24fbe420d7fc681d4d67 Mon Sep 17 00:00:00 2001
From: Cameron McCormack <cam@mcc.id.au>
Date: Sat, 30 Mar 2019 00:16:01 +0000
Subject: [PATCH 13/59] style: Factor out some of style_derive.

Differential Revision: https://phabricator.services.mozilla.com/D17188
---
 components/derive_common/Cargo.toml              | 16 ++++++++++++++++
 components/{style_derive => derive_common}/cg.rs |  0
 components/derive_common/lib.rs                  | 14 ++++++++++++++
 components/style_derive/Cargo.toml               |  1 +
 components/style_derive/animate.rs               |  2 +-
 .../style_derive/compute_squared_distance.rs     |  2 +-
 components/style_derive/lib.rs                   |  2 +-
 components/style_derive/parse.rs                 |  2 +-
 components/style_derive/specified_value_info.rs  |  2 +-
 components/style_derive/to_animated_value.rs     |  2 +-
 components/style_derive/to_animated_zero.rs      |  2 +-
 components/style_derive/to_computed_value.rs     |  2 +-
 components/style_derive/to_css.rs                |  2 +-
 13 files changed, 40 insertions(+), 9 deletions(-)
 create mode 100644 components/derive_common/Cargo.toml
 rename components/{style_derive => derive_common}/cg.rs (100%)
 create mode 100644 components/derive_common/lib.rs

diff --git a/components/derive_common/Cargo.toml b/components/derive_common/Cargo.toml
new file mode 100644
index 00000000000..2a4fac64405
--- /dev/null
+++ b/components/derive_common/Cargo.toml
@@ -0,0 +1,16 @@
+[package]
+name = "derive_common"
+version = "0.0.1"
+authors = ["The Servo Project Developers"]
+license = "MPL-2.0"
+publish = false
+
+[lib]
+path = "lib.rs"
+
+[dependencies]
+darling = "0.8"
+proc-macro2 = "0.4"
+quote = "0.6"
+syn = { version = "0.15", features = ["visit"] }
+synstructure = "0.10"
diff --git a/components/style_derive/cg.rs b/components/derive_common/cg.rs
similarity index 100%
rename from components/style_derive/cg.rs
rename to components/derive_common/cg.rs
diff --git a/components/derive_common/lib.rs b/components/derive_common/lib.rs
new file mode 100644
index 00000000000..1e8d20aa32d
--- /dev/null
+++ b/components/derive_common/lib.rs
@@ -0,0 +1,14 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+extern crate darling;
+extern crate proc_macro;
+extern crate proc_macro2;
+#[macro_use]
+extern crate quote;
+#[macro_use]
+extern crate syn;
+extern crate synstructure;
+
+pub mod cg;
diff --git a/components/style_derive/Cargo.toml b/components/style_derive/Cargo.toml
index 13bd8854948..38c68ac0e36 100644
--- a/components/style_derive/Cargo.toml
+++ b/components/style_derive/Cargo.toml
@@ -11,6 +11,7 @@ proc-macro = true
 
 [dependencies]
 darling = "0.8"
+derive_common = { path = "../derive_common" }
 proc-macro2 = "0.4"
 quote = "0.6"
 syn = { version = "0.15", features = ["visit"] }
diff --git a/components/style_derive/animate.rs b/components/style_derive/animate.rs
index d9674e444c3..ccccdf9d0df 100644
--- a/components/style_derive/animate.rs
+++ b/components/style_derive/animate.rs
@@ -2,8 +2,8 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
 
-use crate::cg;
 use darling::util::IdentList;
+use derive_common::cg;
 use proc_macro2::TokenStream;
 use quote::TokenStreamExt;
 use syn::{DeriveInput, Path, WhereClause};
diff --git a/components/style_derive/compute_squared_distance.rs b/components/style_derive/compute_squared_distance.rs
index d8cf2f6dd18..68c8fdec4c5 100644
--- a/components/style_derive/compute_squared_distance.rs
+++ b/components/style_derive/compute_squared_distance.rs
@@ -3,7 +3,7 @@
  * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
 
 use crate::animate::{AnimationFieldAttrs, AnimationInputAttrs, AnimationVariantAttrs};
-use crate::cg;
+use derive_common::cg;
 use proc_macro2::TokenStream;
 use quote::TokenStreamExt;
 use syn::{DeriveInput, Path};
diff --git a/components/style_derive/lib.rs b/components/style_derive/lib.rs
index 8631f2a33ea..85791c32783 100644
--- a/components/style_derive/lib.rs
+++ b/components/style_derive/lib.rs
@@ -6,6 +6,7 @@
 
 #[macro_use]
 extern crate darling;
+extern crate derive_common;
 extern crate proc_macro;
 extern crate proc_macro2;
 #[macro_use]
@@ -17,7 +18,6 @@ extern crate synstructure;
 use proc_macro::TokenStream;
 
 mod animate;
-mod cg;
 mod compute_squared_distance;
 mod parse;
 mod specified_value_info;
diff --git a/components/style_derive/parse.rs b/components/style_derive/parse.rs
index b9b7ae37e1c..80c214bd734 100644
--- a/components/style_derive/parse.rs
+++ b/components/style_derive/parse.rs
@@ -2,8 +2,8 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
 
-use crate::cg;
 use crate::to_css::CssVariantAttrs;
+use derive_common::cg;
 use proc_macro2::TokenStream;
 use syn::{self, DeriveInput, Path};
 use synstructure::{Structure, VariantInfo};
diff --git a/components/style_derive/specified_value_info.rs b/components/style_derive/specified_value_info.rs
index 4fa11faca84..79e88e9459a 100644
--- a/components/style_derive/specified_value_info.rs
+++ b/components/style_derive/specified_value_info.rs
@@ -2,9 +2,9 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
 
-use crate::cg;
 use crate::parse::ParseVariantAttrs;
 use crate::to_css::{CssFieldAttrs, CssInputAttrs, CssVariantAttrs};
+use derive_common::cg;
 use proc_macro2::TokenStream;
 use quote::TokenStreamExt;
 use syn::{Data, DeriveInput, Fields, Ident, Type};
diff --git a/components/style_derive/to_animated_value.rs b/components/style_derive/to_animated_value.rs
index 1aba9b3327e..17c313e1ed0 100644
--- a/components/style_derive/to_animated_value.rs
+++ b/components/style_derive/to_animated_value.rs
@@ -2,7 +2,7 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
 
-use crate::cg;
+use derive_common::cg;
 use proc_macro2::{Span, TokenStream};
 use syn::{DeriveInput, Ident};
 use synstructure::BindStyle;
diff --git a/components/style_derive/to_animated_zero.rs b/components/style_derive/to_animated_zero.rs
index 523ef9b7a9f..6f0c2fe7ff2 100644
--- a/components/style_derive/to_animated_zero.rs
+++ b/components/style_derive/to_animated_zero.rs
@@ -3,7 +3,7 @@
  * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
 
 use crate::animate::{AnimationFieldAttrs, AnimationInputAttrs, AnimationVariantAttrs};
-use crate::cg;
+use derive_common::cg;
 use proc_macro2::TokenStream;
 use quote::TokenStreamExt;
 use syn;
diff --git a/components/style_derive/to_computed_value.rs b/components/style_derive/to_computed_value.rs
index b0b2aa6af63..21efae17c66 100644
--- a/components/style_derive/to_computed_value.rs
+++ b/components/style_derive/to_computed_value.rs
@@ -2,7 +2,7 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
 
-use crate::cg;
+use derive_common::cg;
 use proc_macro2::{Span, TokenStream};
 use syn::{DeriveInput, Ident};
 use synstructure::BindStyle;
diff --git a/components/style_derive/to_css.rs b/components/style_derive/to_css.rs
index 249ff2969cd..dfd5bc8193f 100644
--- a/components/style_derive/to_css.rs
+++ b/components/style_derive/to_css.rs
@@ -2,8 +2,8 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
 
-use crate::cg;
 use darling::util::Override;
+use derive_common::cg;
 use proc_macro2::TokenStream;
 use quote::{ToTokens, TokenStreamExt};
 use syn::{self, Data, Path, WhereClause};

From f6ef35c5d323bef6fdc3d9fbd6048d4a350ef2cb Mon Sep 17 00:00:00 2001
From: Cameron McCormack <cam@mcc.id.au>
Date: Sat, 30 Mar 2019 00:16:08 +0000
Subject: [PATCH 14/59] style: Add support for deriving ToShmem.

Differential Revision: https://phabricator.services.mozilla.com/D17189
---
 components/style/Cargo.toml            |  1 +
 components/style/lib.rs                |  2 +
 components/to_shmem_derive/Cargo.toml  | 18 +++++++
 components/to_shmem_derive/lib.rs      | 26 +++++++++
 components/to_shmem_derive/to_shmem.rs | 74 ++++++++++++++++++++++++++
 5 files changed, 121 insertions(+)
 create mode 100644 components/to_shmem_derive/Cargo.toml
 create mode 100644 components/to_shmem_derive/lib.rs
 create mode 100644 components/to_shmem_derive/to_shmem.rs

diff --git a/components/style/Cargo.toml b/components/style/Cargo.toml
index c0dbc02a186..005924cec21 100644
--- a/components/style/Cargo.toml
+++ b/components/style/Cargo.toml
@@ -69,6 +69,7 @@ style_traits = {path = "../style_traits"}
 servo_url = {path = "../url", optional = true}
 thin-slice = "0.1.0"
 to_shmem = {path = "../to_shmem"}
+to_shmem_derive = {path = "../to_shmem_derive"}
 time = "0.1"
 uluru = "0.3"
 unicode-bidi = "0.3"
diff --git a/components/style/lib.rs b/components/style/lib.rs
index 294b8634d56..bd33dbeafe4 100644
--- a/components/style/lib.rs
+++ b/components/style/lib.rs
@@ -100,6 +100,8 @@ extern crate style_traits;
 extern crate thin_slice;
 extern crate time;
 extern crate to_shmem;
+#[macro_use]
+extern crate to_shmem_derive;
 extern crate uluru;
 extern crate unicode_bidi;
 #[allow(unused_extern_crates)]
diff --git a/components/to_shmem_derive/Cargo.toml b/components/to_shmem_derive/Cargo.toml
new file mode 100644
index 00000000000..e5aac7e0aaf
--- /dev/null
+++ b/components/to_shmem_derive/Cargo.toml
@@ -0,0 +1,18 @@
+[package]
+name = "to_shmem_derive"
+version = "0.0.1"
+authors = ["The Servo Project Developers"]
+license = "MPL-2.0"
+publish = false
+
+[lib]
+path = "lib.rs"
+proc-macro = true
+
+[dependencies]
+darling = "0.8"
+derive_common = { path = "../derive_common" }
+proc-macro2 = "0.4"
+quote = "0.6"
+syn = { version = "0.15", features = ["visit"] }
+synstructure = "0.10"
diff --git a/components/to_shmem_derive/lib.rs b/components/to_shmem_derive/lib.rs
new file mode 100644
index 00000000000..b820e7f85d0
--- /dev/null
+++ b/components/to_shmem_derive/lib.rs
@@ -0,0 +1,26 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+#![recursion_limit = "128"]
+
+#[macro_use]
+extern crate darling;
+extern crate derive_common;
+extern crate proc_macro;
+extern crate proc_macro2;
+#[macro_use]
+extern crate quote;
+#[macro_use]
+extern crate syn;
+extern crate synstructure;
+
+use proc_macro::TokenStream;
+
+mod to_shmem;
+
+#[proc_macro_derive(ToShmem, attributes(shmem))]
+pub fn derive_to_shmem(stream: TokenStream) -> TokenStream {
+    let input = syn::parse(stream).unwrap();
+    to_shmem::derive(input).into()
+}
diff --git a/components/to_shmem_derive/to_shmem.rs b/components/to_shmem_derive/to_shmem.rs
new file mode 100644
index 00000000000..5021476aad4
--- /dev/null
+++ b/components/to_shmem_derive/to_shmem.rs
@@ -0,0 +1,74 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+use derive_common::cg;
+use proc_macro2::TokenStream;
+use syn;
+use synstructure::{BindStyle, Structure};
+
+pub fn derive(mut input: syn::DeriveInput) -> TokenStream {
+    let mut where_clause = input.generics.where_clause.take();
+    let attrs = cg::parse_input_attrs::<ShmemInputAttrs>(&input);
+    if !attrs.no_bounds {
+        for param in input.generics.type_params() {
+            cg::add_predicate(
+                &mut where_clause,
+                parse_quote!(#param: ::to_shmem::ToShmem),
+            );
+        }
+    }
+    for variant in Structure::new(&input).variants() {
+        for binding in variant.bindings() {
+            let attrs = cg::parse_field_attrs::<ShmemFieldAttrs>(&binding.ast());
+            if attrs.field_bound {
+                let ty = &binding.ast().ty;
+                cg::add_predicate(
+                    &mut where_clause,
+                    parse_quote!(#ty: ::to_shmem::ToShmem),
+                )
+            }
+        }
+    }
+
+    input.generics.where_clause = where_clause;
+
+    let match_body = cg::fmap_match(&input, BindStyle::Ref, |binding| {
+        quote! {
+            ::std::mem::ManuallyDrop::into_inner(
+                ::to_shmem::ToShmem::to_shmem(#binding, builder)
+            )
+        }
+    });
+
+    let name = &input.ident;
+    let (impl_generics, ty_generics, where_clause) = input.generics.split_for_impl();
+
+    quote! {
+        impl #impl_generics ::to_shmem::ToShmem for #name #ty_generics #where_clause {
+            #[allow(unused_variables)]
+            fn to_shmem(
+                &self,
+                builder: &mut ::to_shmem::SharedMemoryBuilder,
+            ) -> ::std::mem::ManuallyDrop<Self> {
+                ::std::mem::ManuallyDrop::new(
+                    match *self {
+                        #match_body
+                    }
+                )
+            }
+        }
+    }
+}
+
+#[darling(attributes(shmem), default)]
+#[derive(Default, FromDeriveInput)]
+pub struct ShmemInputAttrs {
+    pub no_bounds: bool,
+}
+
+#[darling(attributes(shmem), default)]
+#[derive(Default, FromField)]
+pub struct ShmemFieldAttrs {
+    pub field_bound: bool,
+}

From 7fa7c103d6cbae358aa807b931859935173d00a0 Mon Sep 17 00:00:00 2001
From: Cameron McCormack <cam@mcc.id.au>
Date: Sat, 30 Mar 2019 00:16:11 +0000
Subject: [PATCH 15/59] style: Add simple ToShmem implementations.

Differential Revision: https://phabricator.services.mozilla.com/D17190
---
 components/style/lib.rs                       |  1 -
 .../style/properties/longhands/color.mako.rs  |  3 +
 .../style/properties/properties.mako.rs       |  5 +-
 components/style/stylesheets/import_rule.rs   |  8 +++
 components/style/values/mod.rs                |  3 +
 components/to_shmem/Cargo.toml                |  4 +-
 components/to_shmem/lib.rs                    | 64 +++++++++++++++++++
 7 files changed, 85 insertions(+), 3 deletions(-)

diff --git a/components/style/lib.rs b/components/style/lib.rs
index bd33dbeafe4..cb73df55fcf 100644
--- a/components/style/lib.rs
+++ b/components/style/lib.rs
@@ -100,7 +100,6 @@ extern crate style_traits;
 extern crate thin_slice;
 extern crate time;
 extern crate to_shmem;
-#[macro_use]
 extern crate to_shmem_derive;
 extern crate uluru;
 extern crate unicode_bidi;
diff --git a/components/style/properties/longhands/color.mako.rs b/components/style/properties/longhands/color.mako.rs
index 487814935aa..b367f2bbd86 100644
--- a/components/style/properties/longhands/color.mako.rs
+++ b/components/style/properties/longhands/color.mako.rs
@@ -67,6 +67,7 @@ pub mod system_colors {
     use crate::gecko_bindings::structs::root::mozilla::LookAndFeel_ColorID;
     use std::fmt::{self, Write};
     use style_traits::{CssWriter, ToCss};
+    use to_shmem::impl_trivial_to_shmem;
     use crate::values::computed::{Context, ToComputedValue};
 
     pub type SystemColor = LookAndFeel_ColorID;
@@ -75,6 +76,8 @@ pub mod system_colors {
     // is a bindgen type. So we implement it on the typedef instead.
     malloc_size_of_is_0!(SystemColor);
 
+    impl_trivial_to_shmem!(SystemColor);
+
     impl ToCss for SystemColor {
         fn to_css<W>(&self, dest: &mut CssWriter<W>) -> fmt::Result
         where
diff --git a/components/style/properties/properties.mako.rs b/components/style/properties/properties.mako.rs
index c9bc2bd8e2f..2f1760ada9c 100644
--- a/components/style/properties/properties.mako.rs
+++ b/components/style/properties/properties.mako.rs
@@ -36,6 +36,7 @@ use selectors::parser::SelectorParseErrorKind;
 #[cfg(feature = "servo")] use servo_config::prefs;
 use style_traits::{CssWriter, KeywordsCollectFn, ParseError, ParsingMode};
 use style_traits::{SpecifiedValueInfo, StyleParseErrorKind, ToCss};
+use to_shmem::impl_trivial_to_shmem;
 use crate::stylesheets::{CssRuleType, Origin, UrlExtraData};
 use crate::values::generics::text::LineHeight;
 use crate::values::computed;
@@ -741,11 +742,13 @@ static ${name}: LonghandIdSet = LonghandIdSet {
 </%def>
 
 /// A set of longhand properties
-#[derive(Clone, Debug, Default, MallocSizeOf, PartialEq)]
+#[derive(Clone, Copy, Debug, Default, MallocSizeOf, PartialEq)]
 pub struct LonghandIdSet {
     storage: [u32; (${len(data.longhands)} - 1 + 32) / 32]
 }
 
+impl_trivial_to_shmem!(LonghandIdSet);
+
 /// An iterator over a set of longhand ids.
 pub struct LonghandIdSetIterator<'a> {
     longhands: &'a LonghandIdSet,
diff --git a/components/style/stylesheets/import_rule.rs b/components/style/stylesheets/import_rule.rs
index 357f0476281..ca82dcb864b 100644
--- a/components/style/stylesheets/import_rule.rs
+++ b/components/style/stylesheets/import_rule.rs
@@ -15,7 +15,9 @@ use crate::stylesheets::{CssRule, Origin, StylesheetInDocument};
 use crate::values::CssUrl;
 use cssparser::SourceLocation;
 use std::fmt::{self, Write};
+use std::mem::ManuallyDrop;
 use style_traits::{CssWriter, ToCss};
+use to_shmem::{SharedMemoryBuilder, ToShmem};
 
 /// With asynchronous stylesheet parsing, we can't synchronously create a
 /// GeckoStyleSheet. So we use this placeholder instead.
@@ -180,6 +182,12 @@ pub struct ImportRule {
     pub source_location: SourceLocation,
 }
 
+impl ToShmem for ImportRule {
+    fn to_shmem(&self, _builder: &mut SharedMemoryBuilder) -> ManuallyDrop<Self> {
+        panic!("ToShmem failed for ImportRule: cannot handle imported style sheets")
+    }
+}
+
 impl DeepCloneWithLock for ImportRule {
     fn deep_clone_with_lock(
         &self,
diff --git a/components/style/values/mod.rs b/components/style/values/mod.rs
index e29b8923af7..b555598317b 100644
--- a/components/style/values/mod.rs
+++ b/components/style/values/mod.rs
@@ -17,6 +17,7 @@ use selectors::parser::SelectorParseErrorKind;
 use std::fmt::{self, Debug, Write};
 use std::hash;
 use style_traits::{CssWriter, ParseError, StyleParseErrorKind, ToCss};
+use to_shmem::impl_trivial_to_shmem;
 
 #[cfg(feature = "gecko")]
 pub use crate::gecko::url::CssUrl;
@@ -108,6 +109,8 @@ impl ComputeSquaredDistance for Impossible {
     }
 }
 
+impl_trivial_to_shmem!(Impossible);
+
 impl Parse for Impossible {
     fn parse<'i, 't>(
         _context: &ParserContext,
diff --git a/components/to_shmem/Cargo.toml b/components/to_shmem/Cargo.toml
index 666011d498f..84c28f46251 100644
--- a/components/to_shmem/Cargo.toml
+++ b/components/to_shmem/Cargo.toml
@@ -10,7 +10,9 @@ name = "to_shmem"
 path = "lib.rs"
 
 [features]
-servo = []
+servo = ["serde", "cssparser/serde"]
 gecko = []
 
 [dependencies]
+cssparser = "0.25"
+serde = {version = "1.0", optional = true}
diff --git a/components/to_shmem/lib.rs b/components/to_shmem/lib.rs
index 36b1353d08a..ceffc1c5b87 100644
--- a/components/to_shmem/lib.rs
+++ b/components/to_shmem/lib.rs
@@ -12,13 +12,18 @@
 #![crate_name = "to_shmem"]
 #![crate_type = "rlib"]
 
+extern crate cssparser;
+
 use std::alloc::Layout;
 #[cfg(debug_assertions)]
 use std::any::TypeId;
 use std::isize;
 #[cfg(debug_assertions)]
 use std::collections::HashSet;
+use std::marker::PhantomData;
 use std::mem::{self, ManuallyDrop};
+use std::num::Wrapping;
+use std::ops::Range;
 #[cfg(debug_assertions)]
 use std::os::raw::c_void;
 use std::ptr::{self, NonNull};
@@ -173,3 +178,62 @@ pub trait ToShmem: Sized {
     /// accidentally invoke the destructor of the value that is produced.
     fn to_shmem(&self, builder: &mut SharedMemoryBuilder) -> ManuallyDrop<Self>;
 }
+
+#[macro_export]
+macro_rules! impl_trivial_to_shmem {
+    ($($ty:ty),*) => {$(
+        impl $crate::ToShmem for $ty {
+            fn to_shmem(
+                &self,
+                _builder: &mut $crate::SharedMemoryBuilder,
+            ) -> ::std::mem::ManuallyDrop<Self> {
+                ::std::mem::ManuallyDrop::new(*self)
+            }
+        }
+    )*};
+}
+
+impl_trivial_to_shmem!((), bool, f32, f64, i8, i16, i32, i64, u8, u16, u32, u64, isize, usize);
+
+impl_trivial_to_shmem!(cssparser::RGBA);
+impl_trivial_to_shmem!(cssparser::SourceLocation);
+impl_trivial_to_shmem!(cssparser::TokenSerializationType);
+
+impl<T> ToShmem for PhantomData<T> {
+    fn to_shmem(&self, _builder: &mut SharedMemoryBuilder) -> ManuallyDrop<Self> {
+        ManuallyDrop::new(*self)
+    }
+}
+
+impl<T: ToShmem> ToShmem for Range<T> {
+    fn to_shmem(&self, builder: &mut SharedMemoryBuilder) -> ManuallyDrop<Self> {
+        ManuallyDrop::new(Range {
+            start: ManuallyDrop::into_inner(self.start.to_shmem(builder)),
+            end: ManuallyDrop::into_inner(self.end.to_shmem(builder)),
+        })
+    }
+}
+
+impl ToShmem for cssparser::UnicodeRange {
+    fn to_shmem(&self, _builder: &mut SharedMemoryBuilder) -> ManuallyDrop<Self> {
+        ManuallyDrop::new(cssparser::UnicodeRange {
+            start: self.start,
+            end: self.end,
+        })
+    }
+}
+
+impl<T: ToShmem, U: ToShmem> ToShmem for (T, U) {
+    fn to_shmem(&self, builder: &mut SharedMemoryBuilder) -> ManuallyDrop<Self> {
+        ManuallyDrop::new((
+            ManuallyDrop::into_inner(self.0.to_shmem(builder)),
+            ManuallyDrop::into_inner(self.1.to_shmem(builder)),
+        ))
+    }
+}
+
+impl<T: ToShmem> ToShmem for Wrapping<T> {
+    fn to_shmem(&self, builder: &mut SharedMemoryBuilder) -> ManuallyDrop<Self> {
+        ManuallyDrop::new(Wrapping(ManuallyDrop::into_inner(self.0.to_shmem(builder))))
+    }
+}

From 48718b876c8e5ec888eef16edabba216c6b4e66b Mon Sep 17 00:00:00 2001
From: Cameron McCormack <cam@mcc.id.au>
Date: Sat, 30 Mar 2019 00:16:13 +0000
Subject: [PATCH 16/59] style: Add ToShmem impls for collections and strings.

Differential Revision: https://phabricator.services.mozilla.com/D17191
---
 components/to_shmem/Cargo.toml |   4 +
 components/to_shmem/lib.rs     | 271 +++++++++++++++++++++++++++++++++
 2 files changed, 275 insertions(+)

diff --git a/components/to_shmem/Cargo.toml b/components/to_shmem/Cargo.toml
index 84c28f46251..bebc45e821d 100644
--- a/components/to_shmem/Cargo.toml
+++ b/components/to_shmem/Cargo.toml
@@ -16,3 +16,7 @@ gecko = []
 [dependencies]
 cssparser = "0.25"
 serde = {version = "1.0", optional = true}
+servo_arc = { path = "../servo_arc" }
+smallbitvec = "2.1.1"
+smallvec = "0.6.6"
+thin-slice = "0.1.0"
diff --git a/components/to_shmem/lib.rs b/components/to_shmem/lib.rs
index ceffc1c5b87..db6efe20895 100644
--- a/components/to_shmem/lib.rs
+++ b/components/to_shmem/lib.rs
@@ -13,20 +13,32 @@
 #![crate_type = "rlib"]
 
 extern crate cssparser;
+extern crate servo_arc;
+extern crate smallbitvec;
+extern crate smallvec;
+extern crate thin_slice;
 
+use servo_arc::{Arc, ThinArc};
+use smallbitvec::{InternalStorage, SmallBitVec};
+use smallvec::{Array, SmallVec};
 use std::alloc::Layout;
 #[cfg(debug_assertions)]
 use std::any::TypeId;
 use std::isize;
 #[cfg(debug_assertions)]
 use std::collections::HashSet;
+use std::ffi::CString;
 use std::marker::PhantomData;
 use std::mem::{self, ManuallyDrop};
 use std::num::Wrapping;
 use std::ops::Range;
 #[cfg(debug_assertions)]
 use std::os::raw::c_void;
+use std::os::raw::c_char;
 use std::ptr::{self, NonNull};
+use std::slice;
+use std::str;
+use thin_slice::ThinBoxedSlice;
 
 // Various pointer arithmetic functions in this file can be replaced with
 // functions on `Layout` once they have stabilized:
@@ -237,3 +249,262 @@ impl<T: ToShmem> ToShmem for Wrapping<T> {
         ManuallyDrop::new(Wrapping(ManuallyDrop::into_inner(self.0.to_shmem(builder))))
     }
 }
+
+impl<T: ToShmem> ToShmem for Box<T> {
+    fn to_shmem(&self, builder: &mut SharedMemoryBuilder) -> ManuallyDrop<Self> {
+        // Reserve space for the boxed value.
+        let dest: *mut T = builder.alloc_value();
+
+        // Make a clone of the boxed value with all of its heap allocations
+        // placed in the shared memory buffer.
+        let value = (**self).to_shmem(builder);
+
+        unsafe {
+            // Copy the value into the buffer.
+            ptr::write(dest, ManuallyDrop::into_inner(value));
+
+            ManuallyDrop::new(Box::from_raw(dest))
+        }
+    }
+}
+
+/// Converts all the items in `src` into shared memory form, writes them into
+/// the specified buffer, and returns a pointer to the slice.
+unsafe fn to_shmem_slice_ptr<'a, T, I>(
+    src: I,
+    dest: *mut T,
+    builder: &mut SharedMemoryBuilder,
+) -> *mut [T]
+where
+    T: 'a + ToShmem,
+    I: ExactSizeIterator<Item = &'a T>,
+{
+    let dest = slice::from_raw_parts_mut(dest, src.len());
+
+    // Make a clone of each element from the iterator with its own heap
+    // allocations placed in the buffer, and copy that clone into the buffer.
+    for (src, dest) in src.zip(dest.iter_mut()) {
+        ptr::write(dest, ManuallyDrop::into_inner(src.to_shmem(builder)));
+    }
+
+    dest
+}
+
+/// Writes all the items in `src` into a slice in the shared memory buffer and
+/// returns a pointer to the slice.
+unsafe fn to_shmem_slice<'a, T, I>(src: I, builder: &mut SharedMemoryBuilder) -> *mut [T]
+where
+    T: 'a + ToShmem,
+    I: ExactSizeIterator<Item = &'a T>,
+{
+    let dest = builder.alloc_array(src.len());
+    to_shmem_slice_ptr(src, dest, builder)
+}
+
+impl<T: ToShmem> ToShmem for Box<[T]> {
+    fn to_shmem(&self, builder: &mut SharedMemoryBuilder) -> ManuallyDrop<Self> {
+        unsafe {
+            let dest = to_shmem_slice(self.iter(), builder);
+            ManuallyDrop::new(Box::from_raw(dest))
+        }
+    }
+}
+
+impl<T: ToShmem> ToShmem for ThinBoxedSlice<T> {
+    fn to_shmem(&self, builder: &mut SharedMemoryBuilder) -> ManuallyDrop<Self> {
+        // We could support this if we needed but in practice we will never
+        // need to handle such big ThinBoxedSlices.
+        assert!(
+            self.spilled_storage().is_none(),
+            "ToShmem failed for ThinBoxedSlice: too many entries ({})",
+            self.len(),
+        );
+
+        unsafe {
+            let dest = to_shmem_slice(self.iter(), builder);
+            ManuallyDrop::new(ThinBoxedSlice::from_raw(dest))
+        }
+    }
+}
+
+impl ToShmem for Box<str> {
+    fn to_shmem(&self, builder: &mut SharedMemoryBuilder) -> ManuallyDrop<Self> {
+        // Reserve space for the string bytes.
+        let dest: *mut u8 = builder.alloc_array(self.len());
+
+        unsafe {
+            // Copy the value into the buffer.
+            ptr::copy(self.as_ptr(), dest, self.len());
+
+            ManuallyDrop::new(Box::from_raw(str::from_utf8_unchecked_mut(
+                slice::from_raw_parts_mut(dest, self.len()),
+            )))
+        }
+    }
+}
+
+impl ToShmem for String {
+    fn to_shmem(&self, builder: &mut SharedMemoryBuilder) -> ManuallyDrop<Self> {
+        // Reserve space for the string bytes.
+        let dest: *mut u8 = builder.alloc_array(self.len());
+
+        unsafe {
+            // Copy the value into the buffer.
+            ptr::copy(self.as_ptr(), dest, self.len());
+
+            ManuallyDrop::new(String::from_raw_parts(dest, self.len(), self.len()))
+        }
+    }
+}
+
+impl ToShmem for CString {
+    fn to_shmem(&self, builder: &mut SharedMemoryBuilder) -> ManuallyDrop<Self> {
+        let len = self.as_bytes_with_nul().len();
+
+        // Reserve space for the string bytes.
+        let dest: *mut c_char = builder.alloc_array(len);
+
+        unsafe {
+            // Copy the value into the buffer.
+            ptr::copy(self.as_ptr(), dest, len);
+
+            ManuallyDrop::new(CString::from_raw(dest))
+        }
+    }
+}
+
+impl<T: ToShmem> ToShmem for Vec<T> {
+    fn to_shmem(&self, builder: &mut SharedMemoryBuilder) -> ManuallyDrop<Self> {
+        unsafe {
+            let dest = to_shmem_slice(self.iter(), builder) as *mut T;
+            let dest_vec = Vec::from_raw_parts(dest, self.len(), self.len());
+            ManuallyDrop::new(dest_vec)
+        }
+    }
+}
+
+impl<T: ToShmem, A: Array<Item = T>> ToShmem for SmallVec<A> {
+    fn to_shmem(&self, builder: &mut SharedMemoryBuilder) -> ManuallyDrop<Self> {
+        let dest_vec = unsafe {
+            if self.spilled() {
+                // Place the items in a separate allocation in the shared memory
+                // buffer.
+                let dest = to_shmem_slice(self.iter(), builder) as *mut T;
+                SmallVec::from_raw_parts(dest, self.len(), self.len())
+            } else {
+                // Place the items inline.
+                let mut inline: A = mem::uninitialized();
+                to_shmem_slice_ptr(self.iter(), inline.ptr_mut(), builder);
+                SmallVec::from_buf_and_len(inline, self.len())
+            }
+        };
+
+        ManuallyDrop::new(dest_vec)
+    }
+}
+
+impl<T: ToShmem> ToShmem for Option<T> {
+    fn to_shmem(&self, builder: &mut SharedMemoryBuilder) -> ManuallyDrop<Self> {
+        ManuallyDrop::new(
+            self.as_ref()
+                .map(|v| ManuallyDrop::into_inner(v.to_shmem(builder))),
+        )
+    }
+}
+
+impl<T: 'static + ToShmem> ToShmem for Arc<T> {
+    fn to_shmem(&self, builder: &mut SharedMemoryBuilder) -> ManuallyDrop<Self> {
+        // Assert that we don't encounter any shared references to values we
+        // don't expect.  Those we expect are those noted by calling
+        // add_allowed_duplication_type, and should be types where we're fine
+        // with duplicating any shared references in the shared memory buffer.
+        //
+        // Unfortunately there's no good way to print out the exact type of T
+        // in the assertion message.
+        #[cfg(debug_assertions)]
+        assert!(
+            !builder.shared_values.contains(&self.heap_ptr()) ||
+            builder.allowed_duplication_types.contains(&TypeId::of::<T>()),
+            "ToShmem failed for Arc<T>: encountered a value of type T with multiple references \
+             and which has not been explicitly allowed with an add_allowed_duplication_type call",
+        );
+
+        // Make a clone of the Arc-owned value with all of its heap allocations
+        // placed in the shared memory buffer.
+        let value = (**self).to_shmem(builder);
+
+        // Create a new Arc with the shared value and have it place its
+        // ArcInner in the shared memory buffer.
+        unsafe {
+            let static_arc = Arc::new_static(
+                |layout| builder.alloc(layout),
+                ManuallyDrop::into_inner(value),
+            );
+
+            #[cfg(debug_assertions)]
+            builder.shared_values.insert(self.heap_ptr());
+
+            ManuallyDrop::new(static_arc)
+        }
+    }
+}
+
+impl<H: 'static + ToShmem, T: 'static + ToShmem> ToShmem for ThinArc<H, T> {
+    fn to_shmem(&self, builder: &mut SharedMemoryBuilder) -> ManuallyDrop<Self> {
+        // We don't currently have any shared ThinArc values in stylesheets,
+        // so don't support them for now.
+        #[cfg(debug_assertions)]
+        assert!(
+            !builder.shared_values.contains(&self.heap_ptr()),
+            "ToShmem failed for ThinArc<T>: encountered a value with multiple references, which \
+             is not currently supported",
+        );
+
+        // Make a clone of the Arc-owned header and slice values with all of
+        // their heap allocations placed in the shared memory buffer.
+        let header = self.header.header.to_shmem(builder);
+        let values: Vec<ManuallyDrop<T>> = self
+            .slice
+            .iter()
+            .map(|v| v.to_shmem(builder))
+            .collect();
+
+        // Create a new ThinArc with the shared value and have it place
+        // its ArcInner in the shared memory buffer.
+        unsafe {
+            let static_arc = ThinArc::static_from_header_and_iter(
+                |layout| builder.alloc(layout),
+                ManuallyDrop::into_inner(header),
+                values.into_iter().map(ManuallyDrop::into_inner),
+            );
+
+            #[cfg(debug_assertions)]
+            builder.shared_values.insert(self.heap_ptr());
+
+            ManuallyDrop::new(static_arc)
+        }
+    }
+}
+
+impl ToShmem for SmallBitVec {
+    fn to_shmem(&self, builder: &mut SharedMemoryBuilder) -> ManuallyDrop<Self> {
+        let storage = match self.clone().into_storage() {
+            InternalStorage::Spilled(vs) => {
+                // Reserve space for the boxed slice values.
+                let len = vs.len();
+                let dest: *mut usize = builder.alloc_array(len);
+
+                unsafe {
+                    // Copy the value into the buffer.
+                    let src = vs.as_ptr() as *const usize;
+                    ptr::copy(src, dest, len);
+
+                    let dest_slice = Box::from_raw(slice::from_raw_parts_mut(dest, len) as *mut [usize]);
+                    InternalStorage::Spilled(dest_slice)
+                }
+            }
+            InternalStorage::Inline(x) => InternalStorage::Inline(x),
+        };
+        ManuallyDrop::new(unsafe { SmallBitVec::from_storage(storage) })
+    }
+}

From 8c007ad9990ec70a6f86bed85ef8592f9f726a0b Mon Sep 17 00:00:00 2001
From: Cameron McCormack <cam@mcc.id.au>
Date: Sat, 30 Mar 2019 00:16:15 +0000
Subject: [PATCH 17/59] style: Add ToShmem impl for Atom.

Differential Revision: https://phabricator.services.mozilla.com/D17192
---
 components/style/gecko_string_cache/mod.rs | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/components/style/gecko_string_cache/mod.rs b/components/style/gecko_string_cache/mod.rs
index 9c33f25d9b8..f4c875cb7ad 100644
--- a/components/style/gecko_string_cache/mod.rs
+++ b/components/style/gecko_string_cache/mod.rs
@@ -25,9 +25,11 @@ use std::char::{self, DecodeUtf16};
 use std::fmt::{self, Write};
 use std::hash::{Hash, Hasher};
 use std::iter::Cloned;
+use std::mem::{self, ManuallyDrop};
 use std::ops::Deref;
-use std::{mem, slice, str};
+use std::{slice, str};
 use style_traits::SpecifiedValueInfo;
+use to_shmem::{SharedMemoryBuilder, ToShmem};
 
 #[macro_use]
 #[allow(improper_ctypes, non_camel_case_types, missing_docs)]
@@ -122,6 +124,14 @@ impl Borrow<WeakAtom> for Atom {
     }
 }
 
+impl ToShmem for Atom {
+    fn to_shmem(&self, _builder: &mut SharedMemoryBuilder) -> ManuallyDrop<Self> {
+        assert!(self.is_static(), "ToShmem failed for Atom: must be a static atom: {}", self);
+
+        ManuallyDrop::new(Atom(self.0))
+    }
+}
+
 impl Eq for WeakAtom {}
 impl PartialEq for WeakAtom {
     #[inline]

From b8506e4a554070d4ff31e650093b4a25f0acae7d Mon Sep 17 00:00:00 2001
From: Cameron McCormack <cam@mcc.id.au>
Date: Sat, 30 Mar 2019 00:16:17 +0000
Subject: [PATCH 18/59] style: Add ToShmem impl for shared_lock::Locked.

Depends on D17192

Differential Revision: https://phabricator.services.mozilla.com/D17193
---
 components/style/shared_lock.rs | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/components/style/shared_lock.rs b/components/style/shared_lock.rs
index f708ec58a23..f5019326ee0 100644
--- a/components/style/shared_lock.rs
+++ b/components/style/shared_lock.rs
@@ -16,7 +16,10 @@ use std::fmt;
 #[cfg(feature = "servo")]
 use std::mem;
 #[cfg(feature = "gecko")]
+use std::mem::ManuallyDrop;
+#[cfg(feature = "gecko")]
 use std::ptr;
+use to_shmem::{SharedMemoryBuilder, ToShmem};
 
 /// A shared read/write lock that can protect multiple objects.
 ///
@@ -238,6 +241,26 @@ impl<T> Locked<T> {
     }
 }
 
+#[cfg(feature = "gecko")]
+impl<T: ToShmem> ToShmem for Locked<T> {
+    fn to_shmem(&self, builder: &mut SharedMemoryBuilder) -> ManuallyDrop<Self> {
+        let guard = self.shared_lock.read();
+        ManuallyDrop::new(Locked {
+            shared_lock: SharedRwLock::read_only(),
+            data: UnsafeCell::new(ManuallyDrop::into_inner(
+                self.read_with(&guard).to_shmem(builder),
+            )),
+        })
+    }
+}
+
+#[cfg(feature = "servo")]
+impl<T: ToShmem> ToShmem for Locked<T> {
+    fn to_shmem(&self, _builder: &mut SharedMemoryBuilder) -> ManuallyDrop<Self> {
+        panic!("ToShmem not supported in Servo currently")
+    }
+}
+
 #[allow(dead_code)]
 mod compile_time_assert {
     use super::{SharedRwLockReadGuard, SharedRwLockWriteGuard};

From 41f6e67893f3c6cdc6a4700fa479c892b0c59db8 Mon Sep 17 00:00:00 2001
From: Cameron McCormack <cam@mcc.id.au>
Date: Sat, 30 Mar 2019 00:16:19 +0000
Subject: [PATCH 19/59] style: Add ToShmem impl for URLValueSource.

Differential Revision: https://phabricator.services.mozilla.com/D17194
---
 components/style/gecko/url.rs | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/components/style/gecko/url.rs b/components/style/gecko/url.rs
index e5f1b32e04c..a0bf3ff0829 100644
--- a/components/style/gecko/url.rs
+++ b/components/style/gecko/url.rs
@@ -19,8 +19,10 @@ use nsstring::nsCString;
 use servo_arc::Arc;
 use std::collections::HashMap;
 use std::fmt::{self, Write};
+use std::mem::ManuallyDrop;
 use std::sync::RwLock;
 use style_traits::{CssWriter, ParseError, ToCss};
+use to_shmem::{SharedMemoryBuilder, ToShmem};
 
 /// A CSS url() value for gecko.
 #[css(function = "url")]
@@ -138,6 +140,15 @@ pub enum URLValueSource {
     CORSMode(CORSMode),
 }
 
+impl ToShmem for URLValueSource {
+    fn to_shmem(&self, _builder: &mut SharedMemoryBuilder) -> ManuallyDrop<Self> {
+        ManuallyDrop::new(match self {
+            URLValueSource::URLValue(r) => URLValueSource::CORSMode(r.mCORSMode),
+            URLValueSource::CORSMode(c) => URLValueSource::CORSMode(*c),
+        })
+    }
+}
+
 /// A specified non-image `url()` value.
 #[derive(Clone, Debug, SpecifiedValueInfo, ToCss)]
 pub struct SpecifiedUrl {

From 1f966535ac71bf64fe2d944edeeef854d72cda45 Mon Sep 17 00:00:00 2001
From: Cameron McCormack <cam@mcc.id.au>
Date: Sat, 30 Mar 2019 00:16:21 +0000
Subject: [PATCH 20/59] style: Add ToShmem impl for UrlExtraData.

Differential Revision: https://phabricator.services.mozilla.com/D17195
---
 components/style/stylesheets/mod.rs | 23 ++++++++++++++++++++++-
 1 file changed, 22 insertions(+), 1 deletion(-)

diff --git a/components/style/stylesheets/mod.rs b/components/style/stylesheets/mod.rs
index 8e4ec499a05..3dfc4a02727 100644
--- a/components/style/stylesheets/mod.rs
+++ b/components/style/stylesheets/mod.rs
@@ -37,8 +37,9 @@ use malloc_size_of::{MallocSizeOfOps, MallocUnconditionalShallowSizeOf};
 use servo_arc::Arc;
 use std::fmt;
 #[cfg(feature = "gecko")]
-use std::mem;
+use std::mem::{self, ManuallyDrop};
 use style_traits::ParsingMode;
+use to_shmem::{SharedMemoryBuilder, ToShmem};
 
 pub use self::counter_style_rule::CounterStyleRule;
 pub use self::document_rule::DocumentRule;
@@ -101,6 +102,26 @@ impl Drop for UrlExtraData {
     }
 }
 
+#[cfg(feature = "gecko")]
+impl ToShmem for UrlExtraData {
+    fn to_shmem(&self, _builder: &mut SharedMemoryBuilder) -> ManuallyDrop<Self> {
+        if self.0 & 1 == 0 {
+            let shared_extra_datas = unsafe { &structs::URLExtraData_sShared };
+            let self_ptr = self.as_ref() as *const _ as *mut _;
+            let sheet_id = shared_extra_datas
+                .iter()
+                .position(|r| r.mRawPtr == self_ptr)
+                .expect(
+                    "ToShmem failed for UrlExtraData: expected sheet's URLExtraData to be in \
+                     URLExtraData::sShared",
+                );
+            ManuallyDrop::new(UrlExtraData((sheet_id << 1) | 1))
+        } else {
+            ManuallyDrop::new(UrlExtraData(self.0))
+        }
+    }
+}
+
 #[cfg(feature = "gecko")]
 impl UrlExtraData {
     /// Create a new UrlExtraData wrapping a pointer to the specified Gecko

From 128c6ae94aec7b9df26544c46816158aacd8eb59 Mon Sep 17 00:00:00 2001
From: Cameron McCormack <cam@mcc.id.au>
Date: Sat, 30 Mar 2019 00:16:23 +0000
Subject: [PATCH 21/59] style: Add ToShmem impl for FontFamilyList.

Differential Revision: https://phabricator.services.mozilla.com/D17196
---
 components/style/values/computed/font.rs | 21 ++++++++++++++++++++-
 1 file changed, 20 insertions(+), 1 deletion(-)

diff --git a/components/style/values/computed/font.rs b/components/style/values/computed/font.rs
index 8e51072d9a7..b9b5d5bb6e1 100644
--- a/components/style/values/computed/font.rs
+++ b/components/style/values/computed/font.rs
@@ -25,10 +25,11 @@ use malloc_size_of::{MallocSizeOf, MallocSizeOfOps};
 use std::fmt::{self, Write};
 use std::hash::{Hash, Hasher};
 #[cfg(feature = "gecko")]
-use std::mem;
+use std::mem::{self, ManuallyDrop};
 #[cfg(feature = "servo")]
 use std::slice;
 use style_traits::{CssWriter, ParseError, ToCss};
+use to_shmem::{SharedMemoryBuilder, ToShmem};
 
 pub use crate::values::computed::Length as MozScriptMinSize;
 pub use crate::values::specified::font::{FontSynthesis, MozScriptSizeMultiplier};
@@ -508,6 +509,24 @@ pub enum FontFamilyList {
     Generic(structs::FontFamilyType),
 }
 
+#[cfg(feature = "gecko")]
+impl ToShmem for FontFamilyList {
+    fn to_shmem(&self, _builder: &mut SharedMemoryBuilder) -> ManuallyDrop<Self> {
+        // In practice, the only SharedFontList objects we create from shared
+        // style sheets are ones with a single generic entry.
+        ManuallyDrop::new(match self {
+            FontFamilyList::SharedFontList(r) => {
+                assert!(
+                    r.mNames.len() == 1 && r.mNames[0].mName.mRawPtr.is_null(),
+                    "ToShmem failed for FontFamilyList: cannot handle non-generic families",
+                );
+                FontFamilyList::Generic(r.mNames[0].mType)
+            },
+            FontFamilyList::Generic(t) => FontFamilyList::Generic(*t),
+        })
+    }
+}
+
 #[cfg(feature = "gecko")]
 impl Hash for FontFamilyList {
     fn hash<H>(&self, state: &mut H)

From 40248ae5fdc2e768862a1865b43e0a23e588b303 Mon Sep 17 00:00:00 2001
From: Cameron McCormack <cam@mcc.id.au>
Date: Sat, 30 Mar 2019 00:16:25 +0000
Subject: [PATCH 22/59] style: Add derived ToShmem implementations.

Differential Revision: https://phabricator.services.mozilla.com/D17197
---
 components/selectors/Cargo.toml               |  2 +
 components/selectors/attr.rs                  | 14 ++--
 components/selectors/builder.rs               |  2 +-
 components/selectors/lib.rs                   |  3 +
 components/selectors/parser.rs                | 33 +++++----
 components/style/counter_style/mod.rs         | 24 +++----
 components/style/custom_properties.rs         |  2 +-
 components/style/font_face.rs                 | 16 +++--
 .../gecko/pseudo_element_definition.mako.rs   |  2 +-
 components/style/gecko/selector_parser.rs     |  2 +-
 components/style/gecko/url.rs                 |  8 +--
 .../style/gecko_string_cache/namespace.rs     |  2 +-
 components/style/lib.rs                       |  1 +
 components/style/macros.rs                    |  1 +
 .../style/media_queries/media_condition.rs    |  4 +-
 .../media_queries/media_feature_expression.rs | 12 ++--
 components/style/media_queries/media_list.rs  |  2 +-
 components/style/media_queries/media_query.rs |  8 +--
 .../style/properties/declaration_block.rs     |  2 +-
 components/style/properties/helpers.mako.rs   | 10 +--
 .../style/properties/longhands/font.mako.rs   |  2 +-
 .../style/properties/properties.mako.rs       | 17 ++---
 components/style/selector_parser.rs           |  2 +-
 components/style/stylesheets/document_rule.rs |  8 +--
 .../stylesheets/font_feature_values_rule.rs   | 10 +--
 .../style/stylesheets/keyframes_rule.rs       |  8 +--
 components/style/stylesheets/media_rule.rs    |  2 +-
 components/style/stylesheets/mod.rs           |  2 +-
 .../style/stylesheets/namespace_rule.rs       |  2 +-
 components/style/stylesheets/origin.rs        |  2 +-
 components/style/stylesheets/page_rule.rs     |  2 +-
 components/style/stylesheets/rule_list.rs     |  2 +-
 components/style/stylesheets/rule_parser.rs   |  2 +-
 components/style/stylesheets/style_rule.rs    |  2 +-
 components/style/stylesheets/supports_rule.rs |  8 +--
 components/style/stylesheets/viewport_rule.rs |  8 +--
 components/style/values/computed/font.rs      |  4 +-
 components/style/values/computed/length.rs    |  2 +
 .../style/values/computed/percentage.rs       |  1 +
 .../style/values/generics/background.rs       |  1 +
 .../style/values/generics/basic_shape.rs      | 31 ++++++++-
 components/style/values/generics/border.rs    | 28 ++++++--
 components/style/values/generics/box.rs       |  6 +-
 components/style/values/generics/color.rs     |  5 +-
 components/style/values/generics/column.rs    |  1 +
 components/style/values/generics/counters.rs  | 36 ++++++++--
 components/style/values/generics/easing.rs    | 15 ++++-
 components/style/values/generics/effects.rs   |  3 +
 components/style/values/generics/flex.rs      |  1 +
 components/style/values/generics/font.rs      | 16 ++++-
 components/style/values/generics/gecko.rs     |  2 +-
 components/style/values/generics/grid.rs      | 50 +++++++++++---
 components/style/values/generics/image.rs     | 26 ++++---
 components/style/values/generics/length.rs    |  4 ++
 components/style/values/generics/mod.rs       |  9 ++-
 components/style/values/generics/position.rs  |  2 +
 components/style/values/generics/rect.rs      |  1 +
 components/style/values/generics/size.rs      |  1 +
 components/style/values/generics/svg.rs       |  5 ++
 components/style/values/generics/text.rs      | 15 ++++-
 components/style/values/generics/transform.rs | 53 +++++++++++++--
 components/style/values/generics/ui.rs        |  5 +-
 components/style/values/generics/url.rs       |  1 +
 components/style/values/mod.rs                |  7 +-
 components/style/values/specified/align.rs    | 18 ++---
 components/style/values/specified/angle.rs    |  4 +-
 .../style/values/specified/background.rs      |  3 +-
 components/style/values/specified/border.rs   | 11 ++-
 components/style/values/specified/box.rs      | 67 ++++++++++++++++---
 components/style/values/specified/calc.rs     |  2 +-
 components/style/values/specified/color.rs    |  8 +--
 components/style/values/specified/effects.rs  |  2 +-
 components/style/values/specified/font.rs     | 66 +++++++++++-------
 components/style/values/specified/image.rs    |  4 +-
 components/style/values/specified/length.rs   | 14 ++--
 components/style/values/specified/list.rs     | 13 +++-
 components/style/values/specified/mod.rs      | 14 ++--
 components/style/values/specified/motion.rs   |  1 +
 components/style/values/specified/outline.rs  |  1 +
 .../style/values/specified/percentage.rs      |  2 +-
 components/style/values/specified/position.rs | 34 ++++++++--
 .../style/values/specified/resolution.rs      |  2 +-
 components/style/values/specified/svg.rs      |  8 ++-
 components/style/values/specified/svg_path.rs | 14 +++-
 components/style/values/specified/table.rs    | 10 ++-
 components/style/values/specified/text.rs     | 35 +++++++---
 components/style/values/specified/time.rs     |  4 +-
 .../style/values/specified/transform.rs       |  2 +-
 components/style/values/specified/ui.rs       |  6 +-
 components/style_traits/Cargo.toml            |  2 +
 components/style_traits/lib.rs                |  3 +
 components/style_traits/values.rs             |  4 +-
 components/style_traits/viewport.rs           |  2 +-
 93 files changed, 649 insertions(+), 267 deletions(-)

diff --git a/components/selectors/Cargo.toml b/components/selectors/Cargo.toml
index bb8e5d7f81b..ed34c9084d2 100644
--- a/components/selectors/Cargo.toml
+++ b/components/selectors/Cargo.toml
@@ -31,6 +31,8 @@ precomputed-hash = "0.1"
 servo_arc = { version = "0.1", path = "../servo_arc" }
 smallvec = "0.6"
 thin-slice = "0.1.0"
+to_shmem = { path = "../to_shmem" }
+to_shmem_derive = { path = "../to_shmem_derive" }
 
 [build-dependencies]
 phf_codegen = "0.7.18"
diff --git a/components/selectors/attr.rs b/components/selectors/attr.rs
index 36d31e11345..96abbe1c132 100644
--- a/components/selectors/attr.rs
+++ b/components/selectors/attr.rs
@@ -6,11 +6,15 @@ use crate::parser::SelectorImpl;
 use cssparser::ToCss;
 use std::fmt;
 
-#[derive(Clone, Eq, PartialEq)]
+#[derive(Clone, Eq, PartialEq, ToShmem)]
+#[shmem(no_bounds)]
 pub struct AttrSelectorWithOptionalNamespace<Impl: SelectorImpl> {
+    #[shmem(field_bound)]
     pub namespace: Option<NamespaceConstraint<(Impl::NamespacePrefix, Impl::NamespaceUrl)>>,
+    #[shmem(field_bound)]
     pub local_name: Impl::LocalName,
     pub local_name_lower: Impl::LocalName,
+    #[shmem(field_bound)]
     pub operation: ParsedAttrSelectorOperation<Impl::AttrValue>,
     pub never_matches: bool,
 }
@@ -24,7 +28,7 @@ impl<Impl: SelectorImpl> AttrSelectorWithOptionalNamespace<Impl> {
     }
 }
 
-#[derive(Clone, Eq, PartialEq)]
+#[derive(Clone, Eq, PartialEq, ToShmem)]
 pub enum NamespaceConstraint<NamespaceUrl> {
     Any,
 
@@ -32,7 +36,7 @@ pub enum NamespaceConstraint<NamespaceUrl> {
     Specific(NamespaceUrl),
 }
 
-#[derive(Clone, Eq, PartialEq)]
+#[derive(Clone, Eq, PartialEq, ToShmem)]
 pub enum ParsedAttrSelectorOperation<AttrValue> {
     Exists,
     WithValue {
@@ -72,7 +76,7 @@ impl<AttrValue> AttrSelectorOperation<AttrValue> {
     }
 }
 
-#[derive(Clone, Copy, Eq, PartialEq)]
+#[derive(Clone, Copy, Eq, PartialEq, ToShmem)]
 pub enum AttrSelectorOperator {
     Equal,
     Includes,
@@ -132,7 +136,7 @@ impl AttrSelectorOperator {
 /// The definition of whitespace per CSS Selectors Level 3 § 4.
 pub static SELECTOR_WHITESPACE: &'static [char] = &[' ', '\t', '\n', '\r', '\x0C'];
 
-#[derive(Clone, Copy, Debug, Eq, PartialEq)]
+#[derive(Clone, Copy, Debug, Eq, PartialEq, ToShmem)]
 pub enum ParsedCaseSensitivity {
     // 's' was specified.
     ExplicitCaseSensitive,
diff --git a/components/selectors/builder.rs b/components/selectors/builder.rs
index 80e8457cfc8..72404de1084 100644
--- a/components/selectors/builder.rs
+++ b/components/selectors/builder.rs
@@ -199,7 +199,7 @@ pub const HAS_SLOTTED_BIT: u32 = 1 << 31;
 
 /// We use ten bits for each specificity kind (id, class, element), and the two
 /// high bits for the pseudo and slotted flags.
-#[derive(Clone, Copy, Debug, Eq, PartialEq)]
+#[derive(Clone, Copy, Debug, Eq, PartialEq, ToShmem)]
 pub struct SpecificityAndFlags(pub u32);
 
 impl SpecificityAndFlags {
diff --git a/components/selectors/lib.rs b/components/selectors/lib.rs
index 1d9bf58edb3..e8d8062dff7 100644
--- a/components/selectors/lib.rs
+++ b/components/selectors/lib.rs
@@ -21,6 +21,9 @@ extern crate precomputed_hash;
 extern crate servo_arc;
 extern crate smallvec;
 extern crate thin_slice;
+extern crate to_shmem;
+#[macro_use]
+extern crate to_shmem_derive;
 
 pub mod attr;
 pub mod bloom;
diff --git a/components/selectors/parser.rs b/components/selectors/parser.rs
index 488628cd712..765c0d842c1 100644
--- a/components/selectors/parser.rs
+++ b/components/selectors/parser.rs
@@ -221,8 +221,9 @@ pub trait Parser<'i> {
     }
 }
 
-#[derive(Clone, Debug, Eq, PartialEq)]
-pub struct SelectorList<Impl: SelectorImpl>(pub SmallVec<[Selector<Impl>; 1]>);
+#[derive(Clone, Debug, Eq, PartialEq, ToShmem)]
+#[shmem(no_bounds)]
+pub struct SelectorList<Impl: SelectorImpl>(#[shmem(field_bound)] pub SmallVec<[Selector<Impl>; 1]>);
 
 impl<Impl: SelectorImpl> SelectorList<Impl> {
     /// Parse a comma-separated list of Selectors.
@@ -507,8 +508,9 @@ pub fn namespace_empty_string<Impl: SelectorImpl>() -> Impl::NamespaceUrl {
 ///
 /// This reordering doesn't change the semantics of selector matching, and we
 /// handle it in to_css to make it invisible to serialization.
-#[derive(Clone, Eq, PartialEq)]
-pub struct Selector<Impl: SelectorImpl>(ThinArc<SpecificityAndFlags, Component<Impl>>);
+#[derive(Clone, Eq, PartialEq, ToShmem)]
+#[shmem(no_bounds)]
+pub struct Selector<Impl: SelectorImpl>(#[shmem(field_bound)] ThinArc<SpecificityAndFlags, Component<Impl>>);
 
 impl<Impl: SelectorImpl> Selector<Impl> {
     #[inline]
@@ -776,7 +778,7 @@ impl<'a, Impl: SelectorImpl> Iterator for AncestorIter<'a, Impl> {
     }
 }
 
-#[derive(Clone, Copy, Debug, Eq, PartialEq)]
+#[derive(Clone, Copy, Debug, Eq, PartialEq, ToShmem)]
 pub enum Combinator {
     Child,        //  >
     Descendant,   // space
@@ -824,22 +826,24 @@ impl Combinator {
 /// optimal packing and cache performance, see [1].
 ///
 /// [1] https://bugzilla.mozilla.org/show_bug.cgi?id=1357973
-#[derive(Clone, Eq, PartialEq)]
+#[derive(Clone, Eq, PartialEq, ToShmem)]
+#[shmem(no_bounds)]
 pub enum Component<Impl: SelectorImpl> {
     Combinator(Combinator),
 
     ExplicitAnyNamespace,
     ExplicitNoNamespace,
-    DefaultNamespace(Impl::NamespaceUrl),
-    Namespace(Impl::NamespacePrefix, Impl::NamespaceUrl),
+    DefaultNamespace(#[shmem(field_bound)] Impl::NamespaceUrl),
+    Namespace(#[shmem(field_bound)] Impl::NamespacePrefix, #[shmem(field_bound)] Impl::NamespaceUrl),
 
     ExplicitUniversalType,
     LocalName(LocalName<Impl>),
 
-    ID(Impl::Identifier),
-    Class(Impl::ClassName),
+    ID(#[shmem(field_bound)] Impl::Identifier),
+    Class(#[shmem(field_bound)] Impl::ClassName),
 
     AttributeInNoNamespaceExists {
+        #[shmem(field_bound)]
         local_name: Impl::LocalName,
         local_name_lower: Impl::LocalName,
     },
@@ -847,6 +851,7 @@ pub enum Component<Impl: SelectorImpl> {
     AttributeInNoNamespace {
         local_name: Impl::LocalName,
         operator: AttrSelectorOperator,
+        #[shmem(field_bound)]
         value: Impl::AttrValue,
         case_sensitivity: ParsedCaseSensitivity,
         never_matches: bool,
@@ -878,7 +883,7 @@ pub enum Component<Impl: SelectorImpl> {
     FirstOfType,
     LastOfType,
     OnlyOfType,
-    NonTSPseudoClass(Impl::NonTSPseudoClass),
+    NonTSPseudoClass(#[shmem(field_bound)] Impl::NonTSPseudoClass),
     /// The ::slotted() pseudo-element (which isn't actually a pseudo-element,
     /// and probably should be a pseudo-class):
     ///
@@ -902,7 +907,7 @@ pub enum Component<Impl: SelectorImpl> {
     ///
     /// See https://github.com/w3c/csswg-drafts/issues/2158
     Host(Option<Selector<Impl>>),
-    PseudoElement(Impl::PseudoElement),
+    PseudoElement(#[shmem(field_bound)] Impl::PseudoElement),
 }
 
 impl<Impl: SelectorImpl> Component<Impl> {
@@ -957,8 +962,10 @@ impl<Impl: SelectorImpl> Component<Impl> {
     }
 }
 
-#[derive(Clone, Eq, PartialEq)]
+#[derive(Clone, Eq, PartialEq, ToShmem)]
+#[shmem(no_bounds)]
 pub struct LocalName<Impl: SelectorImpl> {
+    #[shmem(field_bound)]
     pub name: Impl::LocalName,
     pub lower_name: Impl::LocalName,
 }
diff --git a/components/style/counter_style/mod.rs b/components/style/counter_style/mod.rs
index 0daa0632739..77de5f52d2b 100644
--- a/components/style/counter_style/mod.rs
+++ b/components/style/counter_style/mod.rs
@@ -164,7 +164,7 @@ macro_rules! counter_style_descriptors {
         $( #[$doc: meta] $name: tt $ident: ident / $setter: ident [$checker: tt]: $ty: ty, )+
     ) => {
         /// An @counter-style rule
-        #[derive(Clone, Debug)]
+        #[derive(Clone, Debug, ToShmem)]
         pub struct CounterStyleRuleData {
             name: CustomIdent,
             generation: Wrapping<u32>,
@@ -337,7 +337,7 @@ impl CounterStyleRuleData {
 }
 
 /// <https://drafts.csswg.org/css-counter-styles/#counter-style-system>
-#[derive(Clone, Debug)]
+#[derive(Clone, Debug, ToShmem)]
 pub enum System {
     /// 'cyclic'
     Cyclic,
@@ -410,7 +410,7 @@ impl ToCss for System {
 
 /// <https://drafts.csswg.org/css-counter-styles/#typedef-symbol>
 #[cfg_attr(feature = "gecko", derive(MallocSizeOf))]
-#[derive(Clone, Debug, Eq, PartialEq, ToComputedValue, ToCss)]
+#[derive(Clone, Debug, Eq, PartialEq, ToComputedValue, ToCss, ToShmem)]
 pub enum Symbol {
     /// <string>
     String(String),
@@ -447,7 +447,7 @@ impl Symbol {
 }
 
 /// <https://drafts.csswg.org/css-counter-styles/#counter-style-negative>
-#[derive(Clone, Debug, ToCss)]
+#[derive(Clone, Debug, ToCss, ToShmem)]
 pub struct Negative(pub Symbol, pub Option<Symbol>);
 
 impl Parse for Negative {
@@ -465,11 +465,11 @@ impl Parse for Negative {
 /// <https://drafts.csswg.org/css-counter-styles/#counter-style-range>
 ///
 /// Empty Vec represents 'auto'
-#[derive(Clone, Debug)]
+#[derive(Clone, Debug, ToShmem)]
 pub struct Ranges(pub Vec<Range<CounterBound>>);
 
 /// A bound found in `Ranges`.
-#[derive(Clone, Copy, Debug, ToCss)]
+#[derive(Clone, Copy, Debug, ToCss, ToShmem)]
 pub enum CounterBound {
     /// An integer bound.
     Integer(Integer),
@@ -548,7 +548,7 @@ where
 }
 
 /// <https://drafts.csswg.org/css-counter-styles/#counter-style-pad>
-#[derive(Clone, Debug, ToCss)]
+#[derive(Clone, Debug, ToCss, ToShmem)]
 pub struct Pad(pub Integer, pub Symbol);
 
 impl Parse for Pad {
@@ -564,7 +564,7 @@ impl Parse for Pad {
 }
 
 /// <https://drafts.csswg.org/css-counter-styles/#counter-style-fallback>
-#[derive(Clone, Debug, ToCss)]
+#[derive(Clone, Debug, ToCss, ToShmem)]
 pub struct Fallback(pub CustomIdent);
 
 impl Parse for Fallback {
@@ -578,7 +578,7 @@ impl Parse for Fallback {
 
 /// <https://drafts.csswg.org/css-counter-styles/#descdef-counter-style-symbols>
 #[cfg_attr(feature = "gecko", derive(MallocSizeOf))]
-#[derive(Clone, Debug, Eq, PartialEq, ToComputedValue, ToCss)]
+#[derive(Clone, Debug, Eq, PartialEq, ToComputedValue, ToCss, ToShmem)]
 pub struct Symbols(#[css(iterable)] pub Vec<Symbol>);
 
 impl Parse for Symbols {
@@ -602,7 +602,7 @@ impl Parse for Symbols {
 }
 
 /// <https://drafts.csswg.org/css-counter-styles/#descdef-counter-style-additive-symbols>
-#[derive(Clone, Debug, ToCss)]
+#[derive(Clone, Debug, ToCss, ToShmem)]
 pub struct AdditiveSymbols(pub Vec<AdditiveTuple>);
 
 impl Parse for AdditiveSymbols {
@@ -623,7 +623,7 @@ impl Parse for AdditiveSymbols {
 }
 
 /// <integer> && <symbol>
-#[derive(Clone, Debug, ToCss)]
+#[derive(Clone, Debug, ToCss, ToShmem)]
 pub struct AdditiveTuple {
     /// <integer>
     pub weight: Integer,
@@ -651,7 +651,7 @@ impl Parse for AdditiveTuple {
 }
 
 /// <https://drafts.csswg.org/css-counter-styles/#counter-style-speak-as>
-#[derive(Clone, Debug, ToCss)]
+#[derive(Clone, Debug, ToCss, ToShmem)]
 pub enum SpeakAs {
     /// auto
     Auto,
diff --git a/components/style/custom_properties.rs b/components/style/custom_properties.rs
index 0dbd611820d..639d32a97a9 100644
--- a/components/style/custom_properties.rs
+++ b/components/style/custom_properties.rs
@@ -96,7 +96,7 @@ pub fn parse_name(s: &str) -> Result<&str, ()> {
 ///
 /// We preserve the original CSS for serialization, and also the variable
 /// references to other custom property names.
-#[derive(Clone, Debug, MallocSizeOf, PartialEq)]
+#[derive(Clone, Debug, MallocSizeOf, PartialEq, ToShmem)]
 pub struct VariableValue {
     css: String,
 
diff --git a/components/style/font_face.rs b/components/style/font_face.rs
index 12ebe3b9864..655c8846f76 100644
--- a/components/style/font_face.rs
+++ b/components/style/font_face.rs
@@ -34,7 +34,7 @@ use style_traits::{StyleParseErrorKind, ToCss};
 
 /// A source for a font-face rule.
 #[cfg_attr(feature = "servo", derive(Deserialize, Serialize))]
-#[derive(Clone, Debug, Eq, PartialEq, ToCss)]
+#[derive(Clone, Debug, Eq, PartialEq, ToCss, ToShmem)]
 pub enum Source {
     /// A `url()` source.
     Url(UrlSource),
@@ -68,7 +68,7 @@ pub enum FontFaceSourceListComponent {
 ///
 /// <https://drafts.csswg.org/css-fonts/#src-desc>
 #[cfg_attr(feature = "servo", derive(Deserialize, Serialize))]
-#[derive(Clone, Debug, Eq, PartialEq)]
+#[derive(Clone, Debug, Eq, PartialEq, ToShmem)]
 pub struct UrlSource {
     /// The specified url.
     pub url: SpecifiedUrl,
@@ -101,7 +101,9 @@ impl ToCss for UrlSource {
 /// on whether and when it is downloaded and ready to use.
 #[allow(missing_docs)]
 #[cfg_attr(feature = "servo", derive(Deserialize, Serialize))]
-#[derive(Clone, Copy, Debug, Eq, MallocSizeOf, Parse, PartialEq, ToComputedValue, ToCss)]
+#[derive(
+    Clone, Copy, Debug, Eq, MallocSizeOf, Parse, PartialEq, ToComputedValue, ToCss, ToShmem,
+)]
 #[repr(u8)]
 pub enum FontDisplay {
     Auto,
@@ -144,7 +146,7 @@ macro_rules! impl_range {
 /// The font-weight descriptor:
 ///
 /// https://drafts.csswg.org/css-fonts-4/#descdef-font-face-font-weight
-#[derive(Clone, Debug, PartialEq)]
+#[derive(Clone, Debug, PartialEq, ToShmem)]
 pub struct FontWeightRange(pub AbsoluteFontWeight, pub AbsoluteFontWeight);
 impl_range!(FontWeightRange, AbsoluteFontWeight);
 
@@ -176,7 +178,7 @@ impl FontWeightRange {
 /// The font-stretch descriptor:
 ///
 /// https://drafts.csswg.org/css-fonts-4/#descdef-font-face-font-stretch
-#[derive(Clone, Debug, PartialEq)]
+#[derive(Clone, Debug, PartialEq, ToShmem)]
 pub struct FontStretchRange(pub FontStretch, pub FontStretch);
 impl_range!(FontStretchRange, FontStretch);
 
@@ -205,7 +207,7 @@ impl FontStretchRange {
 /// The font-style descriptor:
 ///
 /// https://drafts.csswg.org/css-fonts-4/#descdef-font-face-font-style
-#[derive(Clone, Debug, PartialEq)]
+#[derive(Clone, Debug, PartialEq, ToShmem)]
 #[allow(missing_docs)]
 pub enum FontStyle {
     Normal,
@@ -435,7 +437,7 @@ macro_rules! font_face_descriptors_common {
         /// Data inside a `@font-face` rule.
         ///
         /// <https://drafts.csswg.org/css-fonts/#font-face-rule>
-        #[derive(Clone, Debug, PartialEq)]
+        #[derive(Clone, Debug, PartialEq, ToShmem)]
         pub struct FontFaceRuleData {
             $(
                 #[$doc]
diff --git a/components/style/gecko/pseudo_element_definition.mako.rs b/components/style/gecko/pseudo_element_definition.mako.rs
index e2dffcbdd74..a752d84c481 100644
--- a/components/style/gecko/pseudo_element_definition.mako.rs
+++ b/components/style/gecko/pseudo_element_definition.mako.rs
@@ -3,7 +3,7 @@
  * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
 
 /// Gecko's pseudo-element definition.
-#[derive(Clone, Debug, Eq, Hash, MallocSizeOf, PartialEq)]
+#[derive(Clone, Debug, Eq, Hash, MallocSizeOf, PartialEq, ToShmem)]
 pub enum PseudoElement {
     % for pseudo in PSEUDOS:
         /// ${pseudo.value}
diff --git a/components/style/gecko/selector_parser.rs b/components/style/gecko/selector_parser.rs
index b00cb4f909e..41de05c33b9 100644
--- a/components/style/gecko/selector_parser.rs
+++ b/components/style/gecko/selector_parser.rs
@@ -44,7 +44,7 @@ pub type Lang = Atom;
 macro_rules! pseudo_class_name {
     ([$(($css:expr, $name:ident, $gecko_type:tt, $state:tt, $flags:tt),)*]) => {
         /// Our representation of a non tree-structural pseudo-class.
-        #[derive(Clone, Debug, Eq, MallocSizeOf, PartialEq)]
+        #[derive(Clone, Debug, Eq, MallocSizeOf, PartialEq, ToShmem)]
         pub enum NonTSPseudoClass {
             $(
                 #[doc = $css]
diff --git a/components/style/gecko/url.rs b/components/style/gecko/url.rs
index a0bf3ff0829..2c61ab4db0b 100644
--- a/components/style/gecko/url.rs
+++ b/components/style/gecko/url.rs
@@ -26,11 +26,11 @@ use to_shmem::{SharedMemoryBuilder, ToShmem};
 
 /// A CSS url() value for gecko.
 #[css(function = "url")]
-#[derive(Clone, Debug, PartialEq, SpecifiedValueInfo, ToCss)]
+#[derive(Clone, Debug, PartialEq, SpecifiedValueInfo, ToCss, ToShmem)]
 pub struct CssUrl(pub Arc<CssUrlData>);
 
 /// Data shared between CssUrls.
-#[derive(Clone, Debug, PartialEq, SpecifiedValueInfo, ToCss)]
+#[derive(Clone, Debug, PartialEq, SpecifiedValueInfo, ToCss, ToShmem)]
 pub struct CssUrlData {
     /// The URL in unresolved string form.
     serialization: String,
@@ -150,7 +150,7 @@ impl ToShmem for URLValueSource {
 }
 
 /// A specified non-image `url()` value.
-#[derive(Clone, Debug, SpecifiedValueInfo, ToCss)]
+#[derive(Clone, Debug, SpecifiedValueInfo, ToCss, ToShmem)]
 pub struct SpecifiedUrl {
     /// The specified url value.
     pub url: CssUrl,
@@ -276,7 +276,7 @@ impl ToComputedValue for SpecifiedUrl {
 }
 
 /// A specified image `url()` value.
-#[derive(Clone, Debug, Eq, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToCss)]
+#[derive(Clone, Debug, Eq, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToCss, ToShmem)]
 pub struct SpecifiedImageUrl(pub SpecifiedUrl);
 
 impl SpecifiedImageUrl {
diff --git a/components/style/gecko_string_cache/namespace.rs b/components/style/gecko_string_cache/namespace.rs
index 725e1da2169..33883e66941 100644
--- a/components/style/gecko_string_cache/namespace.rs
+++ b/components/style/gecko_string_cache/namespace.rs
@@ -24,7 +24,7 @@ macro_rules! ns {
 }
 
 /// A Gecko namespace is just a wrapped atom.
-#[derive(Clone, Debug, Default, Eq, Hash, MallocSizeOf, PartialEq)]
+#[derive(Clone, Debug, Default, Eq, Hash, MallocSizeOf, PartialEq, ToShmem)]
 pub struct Namespace(pub Atom);
 
 impl PrecomputedHash for Namespace {
diff --git a/components/style/lib.rs b/components/style/lib.rs
index cb73df55fcf..bd33dbeafe4 100644
--- a/components/style/lib.rs
+++ b/components/style/lib.rs
@@ -100,6 +100,7 @@ extern crate style_traits;
 extern crate thin_slice;
 extern crate time;
 extern crate to_shmem;
+#[macro_use]
 extern crate to_shmem_derive;
 extern crate uluru;
 extern crate unicode_bidi;
diff --git a/components/style/macros.rs b/components/style/macros.rs
index fb189837181..654053c140f 100644
--- a/components/style/macros.rs
+++ b/components/style/macros.rs
@@ -80,6 +80,7 @@ macro_rules! define_keyword_type {
             ToAnimatedZero,
             ToComputedValue,
             ToCss,
+            ToShmem,
         )]
         pub struct $name;
 
diff --git a/components/style/media_queries/media_condition.rs b/components/style/media_queries/media_condition.rs
index 7fed56bee85..19e20105819 100644
--- a/components/style/media_queries/media_condition.rs
+++ b/components/style/media_queries/media_condition.rs
@@ -14,7 +14,7 @@ use std::fmt::{self, Write};
 use style_traits::{CssWriter, ParseError, StyleParseErrorKind, ToCss};
 
 /// A binary `and` or `or` operator.
-#[derive(Clone, Copy, Debug, Eq, MallocSizeOf, Parse, PartialEq, ToCss)]
+#[derive(Clone, Copy, Debug, Eq, MallocSizeOf, Parse, PartialEq, ToCss, ToShmem)]
 #[allow(missing_docs)]
 pub enum Operator {
     And,
@@ -29,7 +29,7 @@ enum AllowOr {
 }
 
 /// Represents a media condition.
-#[derive(Clone, Debug, MallocSizeOf, PartialEq)]
+#[derive(Clone, Debug, MallocSizeOf, PartialEq, ToShmem)]
 pub enum MediaCondition {
     /// A simple media feature expression, implicitly parenthesized.
     Feature(MediaFeatureExpression),
diff --git a/components/style/media_queries/media_feature_expression.rs b/components/style/media_queries/media_feature_expression.rs
index 53e24ae5b17..3f8eefbfab5 100644
--- a/components/style/media_queries/media_feature_expression.rs
+++ b/components/style/media_queries/media_feature_expression.rs
@@ -27,7 +27,7 @@ use std::fmt::{self, Write};
 use style_traits::{CssWriter, ParseError, StyleParseErrorKind, ToCss};
 
 /// An aspect ratio, with a numerator and denominator.
-#[derive(Clone, Copy, Debug, Eq, MallocSizeOf, PartialEq)]
+#[derive(Clone, Copy, Debug, Eq, MallocSizeOf, PartialEq, ToShmem)]
 pub struct AspectRatio(pub u32, pub u32);
 
 impl ToCss for AspectRatio {
@@ -51,7 +51,7 @@ impl PartialOrd for AspectRatio {
 }
 
 /// The kind of matching that should be performed on a media feature value.
-#[derive(Clone, Copy, Debug, Eq, MallocSizeOf, PartialEq)]
+#[derive(Clone, Copy, Debug, Eq, MallocSizeOf, PartialEq, ToShmem)]
 pub enum Range {
     /// At least the specified value.
     Min,
@@ -60,7 +60,7 @@ pub enum Range {
 }
 
 /// The operator that was specified in this media feature.
-#[derive(Clone, Copy, Debug, Eq, MallocSizeOf, PartialEq)]
+#[derive(Clone, Copy, Debug, Eq, MallocSizeOf, PartialEq, ToShmem)]
 pub enum Operator {
     /// =
     Equal,
@@ -93,7 +93,7 @@ impl ToCss for Operator {
 ///
 /// Ranged media features are not allowed with operations (that'd make no
 /// sense).
-#[derive(Clone, Copy, Debug, Eq, MallocSizeOf, PartialEq)]
+#[derive(Clone, Copy, Debug, Eq, MallocSizeOf, PartialEq, ToShmem)]
 pub enum RangeOrOperator {
     /// A `Range`.
     Range(Range),
@@ -151,7 +151,7 @@ impl RangeOrOperator {
 
 /// A feature expression contains a reference to the media feature, the value
 /// the media query contained, and the range to evaluate.
-#[derive(Clone, Debug, MallocSizeOf)]
+#[derive(Clone, Debug, MallocSizeOf, ToShmem)]
 pub struct MediaFeatureExpression {
     feature_index: usize,
     value: Option<MediaExpressionValue>,
@@ -467,7 +467,7 @@ impl MediaFeatureExpression {
 /// If the first, this would need to store the relevant values.
 ///
 /// See: https://github.com/w3c/csswg-drafts/issues/1968
-#[derive(Clone, Debug, MallocSizeOf, PartialEq)]
+#[derive(Clone, Debug, MallocSizeOf, PartialEq, ToShmem)]
 pub enum MediaExpressionValue {
     /// A length.
     Length(Length),
diff --git a/components/style/media_queries/media_list.rs b/components/style/media_queries/media_list.rs
index 0acf4f1bdf9..5d150f7db99 100644
--- a/components/style/media_queries/media_list.rs
+++ b/components/style/media_queries/media_list.rs
@@ -15,7 +15,7 @@ use cssparser::{ParserInput, Token};
 
 /// A type that encapsulates a media query list.
 #[css(comma, derive_debug)]
-#[derive(Clone, MallocSizeOf, ToCss)]
+#[derive(Clone, MallocSizeOf, ToCss, ToShmem)]
 pub struct MediaList {
     /// The list of media queries.
     #[css(iterable)]
diff --git a/components/style/media_queries/media_query.rs b/components/style/media_queries/media_query.rs
index f61ac6191fb..1768053dbce 100644
--- a/components/style/media_queries/media_query.rs
+++ b/components/style/media_queries/media_query.rs
@@ -16,7 +16,7 @@ use std::fmt::{self, Write};
 use style_traits::{CssWriter, ParseError, ToCss};
 
 /// <https://drafts.csswg.org/mediaqueries/#mq-prefix>
-#[derive(Clone, Copy, Debug, Eq, MallocSizeOf, Parse, PartialEq, ToCss)]
+#[derive(Clone, Copy, Debug, Eq, MallocSizeOf, Parse, PartialEq, ToCss, ToShmem)]
 pub enum Qualifier {
     /// Hide a media query from legacy UAs:
     /// <https://drafts.csswg.org/mediaqueries/#mq-only>
@@ -27,7 +27,7 @@ pub enum Qualifier {
 }
 
 /// <https://drafts.csswg.org/mediaqueries/#media-types>
-#[derive(Clone, Debug, Eq, MallocSizeOf, PartialEq)]
+#[derive(Clone, Debug, Eq, MallocSizeOf, PartialEq, ToShmem)]
 pub struct MediaType(pub CustomIdent);
 
 impl MediaType {
@@ -58,7 +58,7 @@ impl MediaType {
 /// A [media query][mq].
 ///
 /// [mq]: https://drafts.csswg.org/mediaqueries/
-#[derive(Clone, Debug, MallocSizeOf, PartialEq)]
+#[derive(Clone, Debug, MallocSizeOf, PartialEq, ToShmem)]
 pub struct MediaQuery {
     /// The qualifier for this query.
     pub qualifier: Option<Qualifier>,
@@ -151,7 +151,7 @@ impl MediaQuery {
 }
 
 /// <http://dev.w3.org/csswg/mediaqueries-3/#media0>
-#[derive(Clone, Debug, Eq, MallocSizeOf, PartialEq)]
+#[derive(Clone, Debug, Eq, MallocSizeOf, PartialEq, ToShmem)]
 pub enum MediaQueryType {
     /// A media type that matches every device.
     All,
diff --git a/components/style/properties/declaration_block.rs b/components/style/properties/declaration_block.rs
index 5a2fd6f2236..c86f5bac9ee 100644
--- a/components/style/properties/declaration_block.rs
+++ b/components/style/properties/declaration_block.rs
@@ -90,7 +90,7 @@ impl Importance {
 
 /// Overridden declarations are skipped.
 #[cfg_attr(feature = "gecko", derive(MallocSizeOf))]
-#[derive(Clone)]
+#[derive(Clone, ToShmem)]
 pub struct PropertyDeclarationBlock {
     /// The group of declarations, along with their importance.
     ///
diff --git a/components/style/properties/helpers.mako.rs b/components/style/properties/helpers.mako.rs
index b48f0afbf00..06ffc2ebc41 100644
--- a/components/style/properties/helpers.mako.rs
+++ b/components/style/properties/helpers.mako.rs
@@ -205,7 +205,7 @@
         % if separator == "Comma":
         #[css(comma)]
         % endif
-        #[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToCss)]
+        #[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToCss, ToShmem)]
         pub struct SpecifiedValue(
             % if not allow_empty:
             #[css(iterable)]
@@ -426,7 +426,7 @@
         pub mod computed_value {
             #[cfg_attr(feature = "servo", derive(Deserialize, Serialize))]
             #[derive(Clone, Copy, Debug, Eq, Hash, MallocSizeOf, Parse,
-                     PartialEq, SpecifiedValueInfo, ToCss)]
+                     PartialEq, SpecifiedValueInfo, ToCss, ToShmem)]
             pub enum T {
             % for value in keyword.values_for(product):
                 ${to_camel_case(value)},
@@ -437,7 +437,7 @@
         }
 
         #[cfg_attr(feature = "gecko", derive(MallocSizeOf))]
-        #[derive(Clone, Copy, Debug, Eq, PartialEq, SpecifiedValueInfo, ToCss)]
+        #[derive(Clone, Copy, Debug, Eq, PartialEq, SpecifiedValueInfo, ToCss, ToShmem)]
         pub enum SpecifiedValue {
             Keyword(computed_value::T),
             #[css(skip)]
@@ -589,7 +589,7 @@
         % if extra_specified:
             #[cfg_attr(feature = "servo", derive(Deserialize, Serialize))]
             #[derive(Clone, Copy, Debug, Eq, MallocSizeOf, Parse, PartialEq,
-                     SpecifiedValueInfo, ToCss)]
+                     SpecifiedValueInfo, ToCss, ToShmem)]
             pub enum SpecifiedValue {
                 ${variants(keyword.values_for(product) + extra_specified.split(), bool(extra_specified))}
             }
@@ -600,7 +600,7 @@
             #[cfg_attr(feature = "servo", derive(Deserialize, Serialize))]
             #[derive(Clone, Copy, Debug, Eq, MallocSizeOf, PartialEq, ToCss)]
             % if not extra_specified:
-            #[derive(Parse, SpecifiedValueInfo, ToComputedValue)]
+            #[derive(Parse, SpecifiedValueInfo, ToComputedValue, ToShmem)]
             % endif
             pub enum T {
                 ${variants(data.longhands_by_name[name].keyword.values_for(product), not extra_specified)}
diff --git a/components/style/properties/longhands/font.mako.rs b/components/style/properties/longhands/font.mako.rs
index 466a4471608..a2eb9c3dcff 100644
--- a/components/style/properties/longhands/font.mako.rs
+++ b/components/style/properties/longhands/font.mako.rs
@@ -346,7 +346,7 @@ ${helpers.predefined_type(
                          font_optical_sizing""".split()
         %>
         #[derive(Clone, Copy, Debug, Eq, Hash, MallocSizeOf, PartialEq,
-                 SpecifiedValueInfo, ToCss)]
+                 SpecifiedValueInfo, ToCss, ToShmem)]
         pub enum SystemFont {
             % for font in system_fonts:
                 ${to_camel_case(font)},
diff --git a/components/style/properties/properties.mako.rs b/components/style/properties/properties.mako.rs
index 2f1760ada9c..db9fb9fbd3b 100644
--- a/components/style/properties/properties.mako.rs
+++ b/components/style/properties/properties.mako.rs
@@ -257,6 +257,7 @@ pub mod shorthands {
 %>
 
 /// Servo's representation for a property declaration.
+#[derive(ToShmem)]
 #[repr(u16)]
 pub enum PropertyDeclaration {
     % for variant in variants:
@@ -896,7 +897,7 @@ impl LonghandIdSet {
 
 /// An enum to represent a CSS Wide keyword.
 #[derive(Clone, Copy, Debug, Eq, MallocSizeOf, PartialEq, SpecifiedValueInfo,
-         ToCss)]
+         ToCss, ToShmem)]
 pub enum CSSWideKeyword {
     /// The `initial` keyword.
     Initial,
@@ -996,7 +997,7 @@ pub enum LogicalGroup {
 }
 
 /// An identifier for a given longhand property.
-#[derive(Clone, Copy, Eq, Hash, MallocSizeOf, PartialEq)]
+#[derive(Clone, Copy, Eq, Hash, MallocSizeOf, PartialEq, ToShmem)]
 #[repr(u16)]
 pub enum LonghandId {
     % for i, property in enumerate(data.longhands):
@@ -1338,7 +1339,7 @@ where
 }
 
 /// An identifier for a given shorthand property.
-#[derive(Clone, Copy, Debug, Eq, Hash, MallocSizeOf, PartialEq)]
+#[derive(Clone, Copy, Debug, Eq, Hash, MallocSizeOf, PartialEq, ToShmem)]
 #[repr(u16)]
 pub enum ShorthandId {
     % for i, property in enumerate(data.shorthands):
@@ -1536,7 +1537,7 @@ impl ShorthandId {
 }
 
 /// An unparsed property value that contains `var()` functions.
-#[derive(Debug, Eq, PartialEq)]
+#[derive(Debug, Eq, PartialEq, ToShmem)]
 pub struct UnparsedValue {
     /// The css serialization for this value.
     css: String,
@@ -1957,7 +1958,7 @@ impl PropertyId {
 
 /// A declaration using a CSS-wide keyword.
 #[cfg_attr(feature = "gecko", derive(MallocSizeOf))]
-#[derive(Clone, PartialEq, ToCss)]
+#[derive(Clone, PartialEq, ToCss, ToShmem)]
 pub struct WideKeywordDeclaration {
     #[css(skip)]
     id: LonghandId,
@@ -1966,7 +1967,7 @@ pub struct WideKeywordDeclaration {
 
 /// An unparsed declaration that contains `var()` functions.
 #[cfg_attr(feature = "gecko", derive(MallocSizeOf))]
-#[derive(Clone, PartialEq, ToCss)]
+#[derive(Clone, PartialEq, ToCss, ToShmem)]
 pub struct VariableDeclaration {
     #[css(skip)]
     id: LonghandId,
@@ -1976,7 +1977,7 @@ pub struct VariableDeclaration {
 
 /// A custom property declaration value is either an unparsed value or a CSS
 /// wide-keyword.
-#[derive(Clone, PartialEq, ToCss)]
+#[derive(Clone, PartialEq, ToCss, ToShmem)]
 pub enum CustomDeclarationValue {
     /// A value.
     Value(Arc<crate::custom_properties::SpecifiedValue>),
@@ -1986,7 +1987,7 @@ pub enum CustomDeclarationValue {
 
 /// A custom property declaration with the property name and the declared value.
 #[cfg_attr(feature = "gecko", derive(MallocSizeOf))]
-#[derive(Clone, PartialEq, ToCss)]
+#[derive(Clone, PartialEq, ToCss, ToShmem)]
 pub struct CustomDeclaration {
     /// The name of the custom property.
     #[css(skip)]
diff --git a/components/style/selector_parser.rs b/components/style/selector_parser.rs
index 827c6dea284..a8b5c3bc33e 100644
--- a/components/style/selector_parser.rs
+++ b/components/style/selector_parser.rs
@@ -177,7 +177,7 @@ impl<T> PerPseudoElementMap<T> {
 /// Values for the :dir() pseudo class
 ///
 /// "ltr" and "rtl" values are normalized to lowercase.
-#[derive(Clone, Debug, Eq, MallocSizeOf, PartialEq)]
+#[derive(Clone, Debug, Eq, MallocSizeOf, PartialEq, ToShmem)]
 pub struct Direction(pub Atom);
 
 /// Horizontal values for the :dir() pseudo class
diff --git a/components/style/stylesheets/document_rule.rs b/components/style/stylesheets/document_rule.rs
index c73b96bcd9d..8dd4306c179 100644
--- a/components/style/stylesheets/document_rule.rs
+++ b/components/style/stylesheets/document_rule.rs
@@ -20,7 +20,7 @@ use servo_arc::Arc;
 use std::fmt::{self, Write};
 use style_traits::{CssWriter, ParseError, StyleParseErrorKind, ToCss};
 
-#[derive(Debug)]
+#[derive(Debug, ToShmem)]
 /// A @-moz-document rule
 pub struct DocumentRule {
     /// The parsed condition
@@ -72,7 +72,7 @@ impl DeepCloneWithLock for DocumentRule {
 }
 
 /// The kind of media document that the rule will match.
-#[derive(Clone, Copy, Debug, Parse, PartialEq, ToCss)]
+#[derive(Clone, Copy, Debug, Parse, PartialEq, ToCss, ToShmem)]
 #[allow(missing_docs)]
 pub enum MediaDocumentKind {
     All,
@@ -82,7 +82,7 @@ pub enum MediaDocumentKind {
 }
 
 /// A matching function for a `@document` rule's condition.
-#[derive(Clone, Debug, ToCss)]
+#[derive(Clone, Debug, ToCss, ToShmem)]
 pub enum DocumentMatchingFunction {
     /// Exact URL matching function. It evaluates to true whenever the
     /// URL of the document being styled is exactly the URL given.
@@ -216,7 +216,7 @@ impl DocumentMatchingFunction {
 /// URL matching functions, and the condition evaluates to true whenever any
 /// one of those functions evaluates to true.
 #[css(comma)]
-#[derive(Clone, Debug, ToCss)]
+#[derive(Clone, Debug, ToCss, ToShmem)]
 pub struct DocumentCondition(#[css(iterable)] Vec<DocumentMatchingFunction>);
 
 impl DocumentCondition {
diff --git a/components/style/stylesheets/font_feature_values_rule.rs b/components/style/stylesheets/font_feature_values_rule.rs
index a93ed43d475..74900f96baf 100644
--- a/components/style/stylesheets/font_feature_values_rule.rs
+++ b/components/style/stylesheets/font_feature_values_rule.rs
@@ -30,7 +30,7 @@ use style_traits::{CssWriter, ParseError, StyleParseErrorKind, ToCss};
 /// - `SingleValue` is to keep just one unsigned integer value.
 /// - `PairValues` is to keep one or two unsigned integer values.
 /// - `VectorValues` is to keep a list of unsigned integer values.
-#[derive(Clone, Debug, PartialEq)]
+#[derive(Clone, Debug, PartialEq, ToShmem)]
 pub struct FFVDeclaration<T> {
     /// An `<ident>` for declaration name.
     pub name: Atom,
@@ -58,7 +58,7 @@ pub trait ToGeckoFontFeatureValues {
 }
 
 /// A @font-feature-values block declaration value that keeps one value.
-#[derive(Clone, Debug, PartialEq, ToCss)]
+#[derive(Clone, Debug, PartialEq, ToCss, ToShmem)]
 pub struct SingleValue(pub u32);
 
 impl Parse for SingleValue {
@@ -87,7 +87,7 @@ impl ToGeckoFontFeatureValues for SingleValue {
 }
 
 /// A @font-feature-values block declaration value that keeps one or two values.
-#[derive(Clone, Debug, PartialEq, ToCss)]
+#[derive(Clone, Debug, PartialEq, ToCss, ToShmem)]
 pub struct PairValues(pub u32, pub Option<u32>);
 
 impl Parse for PairValues {
@@ -131,7 +131,7 @@ impl ToGeckoFontFeatureValues for PairValues {
 }
 
 /// A @font-feature-values block declaration value that keeps a list of values.
-#[derive(Clone, Debug, PartialEq, ToCss)]
+#[derive(Clone, Debug, PartialEq, ToCss, ToShmem)]
 pub struct VectorValues(#[css(iterable)] pub Vec<u32>);
 
 impl Parse for VectorValues {
@@ -225,7 +225,7 @@ macro_rules! font_feature_values_blocks {
         /// The [`@font-feature-values`][font-feature-values] at-rule.
         ///
         /// [font-feature-values]: https://drafts.csswg.org/css-fonts-3/#at-font-feature-values-rule
-        #[derive(Clone, Debug, PartialEq)]
+        #[derive(Clone, Debug, PartialEq, ToShmem)]
         pub struct FontFeatureValuesRule {
             /// Font family list for @font-feature-values rule.
             /// Family names cannot contain generic families. FamilyName
diff --git a/components/style/stylesheets/keyframes_rule.rs b/components/style/stylesheets/keyframes_rule.rs
index 662bc9ae481..9efd7f39ccc 100644
--- a/components/style/stylesheets/keyframes_rule.rs
+++ b/components/style/stylesheets/keyframes_rule.rs
@@ -26,7 +26,7 @@ use style_traits::{CssWriter, ParseError, ParsingMode, StyleParseErrorKind, ToCs
 /// A [`@keyframes`][keyframes] rule.
 ///
 /// [keyframes]: https://drafts.csswg.org/css-animations/#keyframes
-#[derive(Debug)]
+#[derive(Debug, ToShmem)]
 pub struct KeyframesRule {
     /// The name of the current animation.
     pub name: KeyframesName,
@@ -99,7 +99,7 @@ impl DeepCloneWithLock for KeyframesRule {
 
 /// A number from 0 to 1, indicating the percentage of the animation when this
 /// keyframe should run.
-#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, PartialOrd)]
+#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, PartialOrd, ToShmem)]
 pub struct KeyframePercentage(pub f32);
 
 impl ::std::cmp::Ord for KeyframePercentage {
@@ -150,7 +150,7 @@ impl KeyframePercentage {
 /// A keyframes selector is a list of percentages or from/to symbols, which are
 /// converted at parse time to percentages.
 #[css(comma)]
-#[derive(Clone, Debug, Eq, PartialEq, ToCss)]
+#[derive(Clone, Debug, Eq, PartialEq, ToCss, ToShmem)]
 pub struct KeyframeSelector(#[css(iterable)] Vec<KeyframePercentage>);
 
 impl KeyframeSelector {
@@ -174,7 +174,7 @@ impl KeyframeSelector {
 }
 
 /// A keyframe.
-#[derive(Debug)]
+#[derive(Debug, ToShmem)]
 pub struct Keyframe {
     /// The selector this keyframe was specified from.
     pub selector: KeyframeSelector,
diff --git a/components/style/stylesheets/media_rule.rs b/components/style/stylesheets/media_rule.rs
index 4266b4c2c10..ea7441a5c09 100644
--- a/components/style/stylesheets/media_rule.rs
+++ b/components/style/stylesheets/media_rule.rs
@@ -21,7 +21,7 @@ use style_traits::{CssWriter, ToCss};
 /// An [`@media`][media] urle.
 ///
 /// [media]: https://drafts.csswg.org/css-conditional/#at-ruledef-media
-#[derive(Debug)]
+#[derive(Debug, ToShmem)]
 pub struct MediaRule {
     /// The list of media queries used by this media rule.
     pub media_queries: Arc<Locked<MediaList>>,
diff --git a/components/style/stylesheets/mod.rs b/components/style/stylesheets/mod.rs
index 3dfc4a02727..133b84fa52f 100644
--- a/components/style/stylesheets/mod.rs
+++ b/components/style/stylesheets/mod.rs
@@ -204,7 +204,7 @@ impl Eq for UrlExtraData {}
 /// A CSS rule.
 ///
 /// TODO(emilio): Lots of spec links should be around.
-#[derive(Clone, Debug)]
+#[derive(Clone, Debug, ToShmem)]
 #[allow(missing_docs)]
 pub enum CssRule {
     // No Charset here, CSSCharsetRule has been removed from CSSOM
diff --git a/components/style/stylesheets/namespace_rule.rs b/components/style/stylesheets/namespace_rule.rs
index ea20cfe1a05..81a92f1c300 100644
--- a/components/style/stylesheets/namespace_rule.rs
+++ b/components/style/stylesheets/namespace_rule.rs
@@ -11,7 +11,7 @@ use cssparser::SourceLocation;
 use std::fmt::{self, Write};
 
 /// A `@namespace` rule.
-#[derive(Clone, Debug, PartialEq)]
+#[derive(Clone, Debug, PartialEq, ToShmem)]
 #[allow(missing_docs)]
 pub struct NamespaceRule {
     /// The namespace prefix, and `None` if it's the default Namespace
diff --git a/components/style/stylesheets/origin.rs b/components/style/stylesheets/origin.rs
index fc89260abd2..783b8f26a8b 100644
--- a/components/style/stylesheets/origin.rs
+++ b/components/style/stylesheets/origin.rs
@@ -10,7 +10,7 @@ use std::ops::BitOrAssign;
 /// Each style rule has an origin, which determines where it enters the cascade.
 ///
 /// <https://drafts.csswg.org/css-cascade/#cascading-origins>
-#[derive(Clone, Copy, Debug, Eq, PartialEq)]
+#[derive(Clone, Copy, Debug, Eq, PartialEq, ToShmem)]
 #[repr(u8)]
 #[cfg_attr(feature = "servo", derive(MallocSizeOf))]
 pub enum Origin {
diff --git a/components/style/stylesheets/page_rule.rs b/components/style/stylesheets/page_rule.rs
index ccb689c1699..3edf562258f 100644
--- a/components/style/stylesheets/page_rule.rs
+++ b/components/style/stylesheets/page_rule.rs
@@ -25,7 +25,7 @@ use std::fmt::{self, Write};
 ///
 /// [page]: https://drafts.csswg.org/css2/page.html#page-box
 /// [page-selectors]: https://drafts.csswg.org/css2/page.html#page-selectors
-#[derive(Debug)]
+#[derive(Debug, ToShmem)]
 pub struct PageRule {
     /// The declaration block this page rule contains.
     pub block: Arc<Locked<PropertyDeclarationBlock>>,
diff --git a/components/style/stylesheets/rule_list.rs b/components/style/stylesheets/rule_list.rs
index c4bf0007bb6..ee2b5347c1e 100644
--- a/components/style/stylesheets/rule_list.rs
+++ b/components/style/stylesheets/rule_list.rs
@@ -17,7 +17,7 @@ use servo_arc::{Arc, RawOffsetArc};
 use std::fmt::{self, Write};
 
 /// A list of CSS rules.
-#[derive(Debug)]
+#[derive(Debug, ToShmem)]
 pub struct CssRules(pub Vec<CssRule>);
 
 impl CssRules {
diff --git a/components/style/stylesheets/rule_parser.rs b/components/style/stylesheets/rule_parser.rs
index 8f4cb088cf0..33190c578b4 100644
--- a/components/style/stylesheets/rule_parser.rs
+++ b/components/style/stylesheets/rule_parser.rs
@@ -133,7 +133,7 @@ pub enum State {
     Body = 4,
 }
 
-#[derive(Clone, Debug, MallocSizeOf)]
+#[derive(Clone, Debug, MallocSizeOf, ToShmem)]
 /// Vendor prefix.
 pub enum VendorPrefix {
     /// -moz prefix.
diff --git a/components/style/stylesheets/style_rule.rs b/components/style/stylesheets/style_rule.rs
index f762d154ad8..905e067f730 100644
--- a/components/style/stylesheets/style_rule.rs
+++ b/components/style/stylesheets/style_rule.rs
@@ -19,7 +19,7 @@ use servo_arc::Arc;
 use std::fmt::{self, Write};
 
 /// A style rule, with selectors and declarations.
-#[derive(Debug)]
+#[derive(Debug, ToShmem)]
 pub struct StyleRule {
     /// The list of selectors in this rule.
     pub selectors: SelectorList<SelectorImpl>,
diff --git a/components/style/stylesheets/supports_rule.rs b/components/style/stylesheets/supports_rule.rs
index 3ed0595aa44..a22acad1aa0 100644
--- a/components/style/stylesheets/supports_rule.rs
+++ b/components/style/stylesheets/supports_rule.rs
@@ -26,7 +26,7 @@ use style_traits::{CssWriter, ParseError, StyleParseErrorKind, ToCss};
 /// An [`@supports`][supports] rule.
 ///
 /// [supports]: https://drafts.csswg.org/css-conditional-3/#at-supports
-#[derive(Debug)]
+#[derive(Debug, ToShmem)]
 pub struct SupportsRule {
     /// The parsed condition
     pub condition: SupportsCondition,
@@ -76,7 +76,7 @@ impl DeepCloneWithLock for SupportsRule {
 /// An @supports condition
 ///
 /// <https://drafts.csswg.org/css-conditional-3/#at-supports>
-#[derive(Clone, Debug)]
+#[derive(Clone, Debug, ToShmem)]
 pub enum SupportsCondition {
     /// `not (condition)`
     Not(Box<SupportsCondition>),
@@ -305,7 +305,7 @@ impl ToCss for SupportsCondition {
     }
 }
 
-#[derive(Clone, Debug)]
+#[derive(Clone, Debug, ToShmem)]
 /// A possibly-invalid CSS selector.
 pub struct RawSelector(pub String);
 
@@ -367,7 +367,7 @@ impl RawSelector {
     }
 }
 
-#[derive(Clone, Debug)]
+#[derive(Clone, Debug, ToShmem)]
 /// A possibly-invalid property declaration
 pub struct Declaration(pub String);
 
diff --git a/components/style/stylesheets/viewport_rule.rs b/components/style/stylesheets/viewport_rule.rs
index 02be35261db..e845930bfbd 100644
--- a/components/style/stylesheets/viewport_rule.rs
+++ b/components/style/stylesheets/viewport_rule.rs
@@ -80,7 +80,7 @@ macro_rules! declare_viewport_descriptor_inner {
         [ ]
         $number_of_variants: expr
     ) => {
-        #[derive(Clone, Debug, PartialEq)]
+        #[derive(Clone, Debug, PartialEq, ToShmem)]
         #[cfg_attr(feature = "servo", derive(MallocSizeOf))]
         #[allow(missing_docs)]
         pub enum ViewportDescriptor {
@@ -147,7 +147,7 @@ trait FromMeta: Sized {
 /// * http://dev.w3.org/csswg/css-device-adapt/#extend-to-zoom
 #[allow(missing_docs)]
 #[cfg_attr(feature = "servo", derive(MallocSizeOf))]
-#[derive(Clone, Debug, PartialEq, ToCss)]
+#[derive(Clone, Debug, PartialEq, ToCss, ToShmem)]
 pub enum ViewportLength {
     Specified(NonNegativeLengthPercentageOrAuto),
     ExtendToZoom,
@@ -225,7 +225,7 @@ struct ViewportRuleParser<'a, 'b: 'a> {
     context: &'a ParserContext<'b>,
 }
 
-#[derive(Clone, Debug, PartialEq)]
+#[derive(Clone, Debug, PartialEq, ToShmem)]
 #[cfg_attr(feature = "servo", derive(MallocSizeOf))]
 #[allow(missing_docs)]
 pub struct ViewportDescriptorDeclaration {
@@ -335,7 +335,7 @@ impl<'a, 'b, 'i> DeclarationParser<'i> for ViewportRuleParser<'a, 'b> {
 }
 
 /// A `@viewport` rule.
-#[derive(Clone, Debug, PartialEq)]
+#[derive(Clone, Debug, PartialEq, ToShmem)]
 #[cfg_attr(feature = "servo", derive(MallocSizeOf))]
 pub struct ViewportRule {
     /// The declarations contained in this @viewport rule.
diff --git a/components/style/values/computed/font.rs b/components/style/values/computed/font.rs
index b9b5d5bb6e1..6bd8cae445b 100644
--- a/components/style/values/computed/font.rs
+++ b/components/style/values/computed/font.rs
@@ -225,7 +225,7 @@ impl ToCss for FontFamily {
     }
 }
 
-#[derive(Clone, Debug, Eq, Hash, MallocSizeOf, PartialEq)]
+#[derive(Clone, Debug, Eq, Hash, MallocSizeOf, PartialEq, ToShmem)]
 #[cfg_attr(feature = "servo", derive(Deserialize, Serialize))]
 /// The name of a font family of choice
 pub struct FamilyName {
@@ -268,7 +268,7 @@ impl ToCss for FamilyName {
     }
 }
 
-#[derive(Clone, Debug, Eq, Hash, MallocSizeOf, PartialEq)]
+#[derive(Clone, Debug, Eq, Hash, MallocSizeOf, PartialEq, ToShmem)]
 #[cfg_attr(feature = "servo", derive(Deserialize, Serialize))]
 /// Font family names must either be given quoted as strings,
 /// or unquoted as a sequence of one or more identifiers.
diff --git a/components/style/values/computed/length.rs b/components/style/values/computed/length.rs
index 1262e4dd1d5..0587dc46791 100644
--- a/components/style/values/computed/length.rs
+++ b/components/style/values/computed/length.rs
@@ -608,6 +608,7 @@ impl Size {
     PartialOrd,
     ToAnimatedValue,
     ToAnimatedZero,
+    ToShmem,
 )]
 #[repr(C)]
 pub struct CSSPixelLength(CSSFloat);
@@ -809,6 +810,7 @@ pub type NonNegativeLengthOrNumber = GenericLengthOrNumber<NonNegativeLength, No
     ToAnimatedZero,
     ToComputedValue,
     ToCss,
+    ToShmem,
 )]
 #[repr(u8)]
 pub enum ExtremumLength {
diff --git a/components/style/values/computed/percentage.rs b/components/style/values/computed/percentage.rs
index 4f39a7a7274..68579f95fb4 100644
--- a/components/style/values/computed/percentage.rs
+++ b/components/style/values/computed/percentage.rs
@@ -27,6 +27,7 @@ use style_traits::{CssWriter, ToCss};
     ToAnimatedValue,
     ToAnimatedZero,
     ToComputedValue,
+    ToShmem,
 )]
 #[repr(C)]
 pub struct Percentage(pub CSSFloat);
diff --git a/components/style/values/generics/background.rs b/components/style/values/generics/background.rs
index 3780f9a4fc3..0ea71713e37 100644
--- a/components/style/values/generics/background.rs
+++ b/components/style/values/generics/background.rs
@@ -27,6 +27,7 @@ fn width_and_height_are_auto<L>(
     ToAnimatedZero,
     ToComputedValue,
     ToCss,
+    ToShmem,
 )]
 #[repr(C, u8)]
 pub enum GenericBackgroundSize<LengthPercent> {
diff --git a/components/style/values/generics/basic_shape.rs b/components/style/values/generics/basic_shape.rs
index 975fbdb797d..2258ce11ade 100644
--- a/components/style/values/generics/basic_shape.rs
+++ b/components/style/values/generics/basic_shape.rs
@@ -31,6 +31,7 @@ pub type ClippingShape<BasicShape, Url> = ShapeSource<BasicShape, GeometryBox, U
     ToAnimatedValue,
     ToComputedValue,
     ToCss,
+    ToShmem,
 )]
 pub enum GeometryBox {
     FillBox,
@@ -58,6 +59,7 @@ pub type FloatAreaShape<BasicShape, Image> = ShapeSource<BasicShape, ShapeBox, I
     ToAnimatedValue,
     ToComputedValue,
     ToCss,
+    ToShmem,
 )]
 pub enum ShapeBox {
     MarginBox,
@@ -79,6 +81,7 @@ pub enum ShapeBox {
     ToAnimatedValue,
     ToComputedValue,
     ToCss,
+    ToShmem,
 )]
 pub enum ShapeSource<BasicShape, ReferenceBox, ImageOrUrl> {
     #[animation(error)]
@@ -104,11 +107,24 @@ pub enum ShapeSource<BasicShape, ReferenceBox, ImageOrUrl> {
     ToAnimatedValue,
     ToComputedValue,
     ToCss,
+    ToShmem,
 )]
 pub enum BasicShape<H, V, LengthPercentage, NonNegativeLengthPercentage> {
-    Inset(#[css(field_bound)] InsetRect<LengthPercentage, NonNegativeLengthPercentage>),
-    Circle(#[css(field_bound)] Circle<H, V, NonNegativeLengthPercentage>),
-    Ellipse(#[css(field_bound)] Ellipse<H, V, NonNegativeLengthPercentage>),
+    Inset(
+        #[css(field_bound)]
+        #[shmem(field_bound)]
+        InsetRect<LengthPercentage, NonNegativeLengthPercentage>,
+    ),
+    Circle(
+        #[css(field_bound)]
+        #[shmem(field_bound)]
+        Circle<H, V, NonNegativeLengthPercentage>,
+    ),
+    Ellipse(
+        #[css(field_bound)]
+        #[shmem(field_bound)]
+        Ellipse<H, V, NonNegativeLengthPercentage>,
+    ),
     Polygon(Polygon<LengthPercentage>),
 }
 
@@ -125,9 +141,11 @@ pub enum BasicShape<H, V, LengthPercentage, NonNegativeLengthPercentage> {
     SpecifiedValueInfo,
     ToAnimatedValue,
     ToComputedValue,
+    ToShmem,
 )]
 pub struct InsetRect<LengthPercentage, NonNegativeLengthPercentage> {
     pub rect: Rect<LengthPercentage>,
+    #[shmem(field_bound)]
     pub round: BorderRadius<NonNegativeLengthPercentage>,
 }
 
@@ -145,6 +163,7 @@ pub struct InsetRect<LengthPercentage, NonNegativeLengthPercentage> {
     SpecifiedValueInfo,
     ToAnimatedValue,
     ToComputedValue,
+    ToShmem,
 )]
 pub struct Circle<H, V, NonNegativeLengthPercentage> {
     pub position: Position<H, V>,
@@ -165,6 +184,7 @@ pub struct Circle<H, V, NonNegativeLengthPercentage> {
     SpecifiedValueInfo,
     ToAnimatedValue,
     ToComputedValue,
+    ToShmem,
 )]
 pub struct Ellipse<H, V, NonNegativeLengthPercentage> {
     pub position: Position<H, V>,
@@ -186,6 +206,7 @@ pub struct Ellipse<H, V, NonNegativeLengthPercentage> {
     ToAnimatedValue,
     ToComputedValue,
     ToCss,
+    ToShmem,
 )]
 pub enum ShapeRadius<NonNegativeLengthPercentage> {
     Length(NonNegativeLengthPercentage),
@@ -208,6 +229,7 @@ pub enum ShapeRadius<NonNegativeLengthPercentage> {
     ToAnimatedValue,
     ToComputedValue,
     ToCss,
+    ToShmem,
 )]
 pub struct Polygon<LengthPercentage> {
     /// The filling rule for a polygon.
@@ -228,6 +250,7 @@ pub struct Polygon<LengthPercentage> {
     ToAnimatedValue,
     ToComputedValue,
     ToCss,
+    ToShmem,
 )]
 pub struct PolygonCoord<LengthPercentage>(pub LengthPercentage, pub LengthPercentage);
 
@@ -249,6 +272,7 @@ pub struct PolygonCoord<LengthPercentage>(pub LengthPercentage, pub LengthPercen
     ToAnimatedValue,
     ToComputedValue,
     ToCss,
+    ToShmem,
 )]
 #[repr(u8)]
 pub enum FillRule {
@@ -270,6 +294,7 @@ pub enum FillRule {
     ToAnimatedValue,
     ToComputedValue,
     ToCss,
+    ToShmem,
 )]
 pub struct Path {
     /// The filling rule for the svg path.
diff --git a/components/style/values/generics/border.rs b/components/style/values/generics/border.rs
index df6427e888f..4652ce5ec85 100644
--- a/components/style/values/generics/border.rs
+++ b/components/style/values/generics/border.rs
@@ -12,7 +12,15 @@ use style_traits::{CssWriter, ToCss};
 
 /// A generic value for a single side of a `border-image-width` property.
 #[derive(
-    Clone, Copy, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss,
+    Clone,
+    Copy,
+    Debug,
+    MallocSizeOf,
+    PartialEq,
+    SpecifiedValueInfo,
+    ToComputedValue,
+    ToCss,
+    ToShmem,
 )]
 pub enum BorderImageSideWidth<LengthPercentage, Number> {
     /// `<length-or-percentage>`
@@ -25,7 +33,15 @@ pub enum BorderImageSideWidth<LengthPercentage, Number> {
 
 /// A generic value for the `border-image-slice` property.
 #[derive(
-    Clone, Copy, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss,
+    Clone,
+    Copy,
+    Debug,
+    MallocSizeOf,
+    PartialEq,
+    SpecifiedValueInfo,
+    ToComputedValue,
+    ToCss,
+    ToShmem,
 )]
 #[repr(C)]
 pub struct GenericBorderImageSlice<NumberOrPercentage> {
@@ -53,9 +69,10 @@ pub use self::GenericBorderImageSlice as BorderImageSlice;
     ToAnimatedZero,
     ToComputedValue,
     ToCss,
+    ToShmem,
 )]
 #[repr(C)]
-pub struct GenericBorderCornerRadius<L>(#[css(field_bound)] pub Size2D<L>);
+pub struct GenericBorderCornerRadius<L>(#[css(field_bound)] #[shmem(field_bound)] pub Size2D<L>);
 
 pub use self::GenericBorderCornerRadius as BorderCornerRadius;
 
@@ -90,9 +107,10 @@ impl<L: Zero> Zero for BorderCornerRadius<L> {
     ToAnimatedZero,
     ToComputedValue,
     ToCss,
+    ToShmem,
 )]
 #[repr(transparent)]
-pub struct BorderSpacing<L>(#[css(field_bound)] pub Size2D<L>);
+pub struct BorderSpacing<L>(#[css(field_bound)] #[shmem(field_bound)] pub Size2D<L>);
 
 impl<L> BorderSpacing<L> {
     /// Trivially create a `BorderCornerRadius`.
@@ -115,10 +133,12 @@ impl<L> BorderSpacing<L> {
     SpecifiedValueInfo,
     ToAnimatedValue,
     ToComputedValue,
+    ToShmem,
 )]
 #[repr(C)]
 pub struct GenericBorderRadius<LengthPercentage> {
     /// The top left radius.
+    #[shmem(field_bound)]
     pub top_left: GenericBorderCornerRadius<LengthPercentage>,
     /// The top right radius.
     pub top_right: GenericBorderCornerRadius<LengthPercentage>,
diff --git a/components/style/values/generics/box.rs b/components/style/values/generics/box.rs
index f49cba4c2e1..91f7cf31828 100644
--- a/components/style/values/generics/box.rs
+++ b/components/style/values/generics/box.rs
@@ -18,6 +18,7 @@ use crate::values::animated::ToAnimatedZero;
     SpecifiedValueInfo,
     ToComputedValue,
     ToCss,
+    ToShmem,
 )]
 pub enum VerticalAlign<LengthPercentage> {
     /// `baseline`
@@ -58,7 +59,9 @@ impl<L> ToAnimatedZero for VerticalAlign<L> {
 }
 
 /// https://drafts.csswg.org/css-animations/#animation-iteration-count
-#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss)]
+#[derive(
+    Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss, ToShmem,
+)]
 pub enum AnimationIterationCount<Number> {
     /// A `<number>` value.
     Number(Number),
@@ -81,6 +84,7 @@ pub enum AnimationIterationCount<Number> {
     ToAnimatedZero,
     ToComputedValue,
     ToCss,
+    ToShmem,
 )]
 #[repr(C, u8)]
 pub enum GenericPerspective<NonNegativeLength> {
diff --git a/components/style/values/generics/color.rs b/components/style/values/generics/color.rs
index 58e4e9fa97c..34b8f0608f8 100644
--- a/components/style/values/generics/color.rs
+++ b/components/style/values/generics/color.rs
@@ -6,7 +6,7 @@
 
 /// Ratios representing the contribution of color and currentcolor to
 /// the final color value.
-#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, ToAnimatedValue)]
+#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, ToAnimatedValue, ToShmem)]
 pub struct ComplexColorRatios {
     /// Numeric color contribution.
     pub bg: f32,
@@ -23,7 +23,7 @@ impl ComplexColorRatios {
 
 /// This enum represents a combined color from a numeric color and
 /// the current foreground color (currentcolor keyword).
-#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, ToAnimatedValue)]
+#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, ToAnimatedValue, ToShmem)]
 pub enum Color<RGBA> {
     ///  Numeric RGBA color.
     Numeric(RGBA),
@@ -90,6 +90,7 @@ impl<RGBA> From<RGBA> for Color<RGBA> {
     ToAnimatedZero,
     ToComputedValue,
     ToCss,
+    ToShmem,
 )]
 pub enum ColorOrAuto<C> {
     /// A `<color>
diff --git a/components/style/values/generics/column.rs b/components/style/values/generics/column.rs
index 6f8c9daef5b..a70d9942ac4 100644
--- a/components/style/values/generics/column.rs
+++ b/components/style/values/generics/column.rs
@@ -19,6 +19,7 @@
     ToAnimatedZero,
     ToComputedValue,
     ToCss,
+    ToShmem,
 )]
 pub enum ColumnCount<PositiveInteger> {
     /// A positive integer.
diff --git a/components/style/values/generics/counters.rs b/components/style/values/generics/counters.rs
index 7bab3c4bbc5..4ca5361520d 100644
--- a/components/style/values/generics/counters.rs
+++ b/components/style/values/generics/counters.rs
@@ -14,7 +14,9 @@ use crate::values::CustomIdent;
 use std::ops::Deref;
 
 /// A name / value pair for counters.
-#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss)]
+#[derive(
+    Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss, ToShmem,
+)]
 pub struct CounterPair<Integer> {
     /// The name of the counter.
     pub name: CustomIdent,
@@ -24,7 +26,15 @@ pub struct CounterPair<Integer> {
 
 /// A generic value for the `counter-increment` property.
 #[derive(
-    Clone, Debug, Default, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss,
+    Clone,
+    Debug,
+    Default,
+    MallocSizeOf,
+    PartialEq,
+    SpecifiedValueInfo,
+    ToComputedValue,
+    ToCss,
+    ToShmem,
 )]
 pub struct CounterIncrement<I>(Counters<I>);
 
@@ -47,7 +57,15 @@ impl<I> Deref for CounterIncrement<I> {
 
 /// A generic value for the `counter-set` and `counter-reset` properties.
 #[derive(
-    Clone, Debug, Default, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss,
+    Clone,
+    Debug,
+    Default,
+    MallocSizeOf,
+    PartialEq,
+    SpecifiedValueInfo,
+    ToComputedValue,
+    ToCss,
+    ToShmem,
 )]
 pub struct CounterSetOrReset<I>(Counters<I>);
 
@@ -71,7 +89,9 @@ impl<I> Deref for CounterSetOrReset<I> {
 /// A generic value for lists of counters.
 ///
 /// Keyword `none` is represented by an empty vector.
-#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss)]
+#[derive(
+    Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss, ToShmem,
+)]
 pub struct Counters<I>(#[css(iterable, if_empty = "none")] Box<[CounterPair<I>]>);
 
 impl<I> Default for Counters<I> {
@@ -102,7 +122,9 @@ fn is_decimal(counter_type: &CounterStyleType) -> bool {
 /// The specified value for the `content` property.
 ///
 /// https://drafts.csswg.org/css-content/#propdef-content
-#[derive(Clone, Debug, Eq, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss)]
+#[derive(
+    Clone, Debug, Eq, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss, ToShmem,
+)]
 pub enum Content<ImageUrl> {
     /// `normal` reserved keyword.
     Normal,
@@ -124,7 +146,9 @@ impl<ImageUrl> Content<ImageUrl> {
 }
 
 /// Items for the `content` property.
-#[derive(Clone, Debug, Eq, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss)]
+#[derive(
+    Clone, Debug, Eq, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss, ToShmem,
+)]
 pub enum ContentItem<ImageUrl> {
     /// Literal string content.
     String(Box<str>),
diff --git a/components/style/values/generics/easing.rs b/components/style/values/generics/easing.rs
index ff4a5a39b5b..90ad530a98a 100644
--- a/components/style/values/generics/easing.rs
+++ b/components/style/values/generics/easing.rs
@@ -10,7 +10,15 @@ use crate::values::CSSFloat;
 
 /// A generic easing function.
 #[derive(
-    Clone, Copy, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss,
+    Clone,
+    Copy,
+    Debug,
+    MallocSizeOf,
+    PartialEq,
+    SpecifiedValueInfo,
+    ToComputedValue,
+    ToCss,
+    ToShmem,
 )]
 #[value_info(ty = "TIMING_FUNCTION")]
 #[repr(u8, C)]
@@ -46,6 +54,7 @@ pub enum TimingFunction<Integer, Number> {
     SpecifiedValueInfo,
     ToComputedValue,
     ToCss,
+    ToShmem,
 )]
 #[repr(u8)]
 pub enum TimingKeyword {
@@ -69,7 +78,9 @@ fn step_position_jump_enabled(_context: &ParserContext) -> bool {
 
 #[allow(missing_docs)]
 #[cfg_attr(feature = "servo", derive(Deserialize, Serialize))]
-#[derive(Clone, Copy, Debug, Eq, MallocSizeOf, Parse, PartialEq, ToComputedValue, ToCss)]
+#[derive(
+    Clone, Copy, Debug, Eq, MallocSizeOf, Parse, PartialEq, ToComputedValue, ToCss, ToShmem,
+)]
 #[repr(u8)]
 pub enum StepPosition {
     #[parse(condition = "step_position_jump_enabled")]
diff --git a/components/style/values/generics/effects.rs b/components/style/values/generics/effects.rs
index 5b755ca3906..744f8ac1fe7 100644
--- a/components/style/values/generics/effects.rs
+++ b/components/style/values/generics/effects.rs
@@ -16,6 +16,7 @@
     ToAnimatedValue,
     ToAnimatedZero,
     ToCss,
+    ToShmem,
 )]
 pub struct BoxShadow<Color, SizeLength, BlurShapeLength, ShapeLength> {
     /// The base shadow.
@@ -41,6 +42,7 @@ pub struct BoxShadow<Color, SizeLength, BlurShapeLength, ShapeLength> {
     ToAnimatedValue,
     ToComputedValue,
     ToCss,
+    ToShmem,
 )]
 pub enum Filter<Angle, Factor, Length, DropShadow, Url> {
     /// `blur(<length>)`
@@ -93,6 +95,7 @@ pub enum Filter<Angle, Factor, Length, DropShadow, Url> {
     ToAnimatedValue,
     ToAnimatedZero,
     ToCss,
+    ToShmem,
 )]
 pub struct SimpleShadow<Color, SizeLength, ShapeLength> {
     /// Color.
diff --git a/components/style/values/generics/flex.rs b/components/style/values/generics/flex.rs
index de67b56e35b..11b2b737902 100644
--- a/components/style/values/generics/flex.rs
+++ b/components/style/values/generics/flex.rs
@@ -19,6 +19,7 @@
     ToAnimatedZero,
     ToComputedValue,
     ToCss,
+    ToShmem,
 )]
 #[repr(C)]
 pub enum GenericFlexBasis<S> {
diff --git a/components/style/values/generics/font.rs b/components/style/values/generics/font.rs
index ee14e15bfe5..cb1ec77e781 100644
--- a/components/style/values/generics/font.rs
+++ b/components/style/values/generics/font.rs
@@ -15,7 +15,9 @@ use style_traits::{CssWriter, KeywordsCollectFn, ParseError};
 use style_traits::{SpecifiedValueInfo, StyleParseErrorKind, ToCss};
 
 /// https://drafts.csswg.org/css-fonts-4/#feature-tag-value
-#[derive(Clone, Debug, Eq, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue)]
+#[derive(
+    Clone, Debug, Eq, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToShmem,
+)]
 pub struct FeatureTagValue<Integer> {
     /// A four-character tag, packed into a u32 (one byte per character).
     pub tag: FontTag,
@@ -56,6 +58,7 @@ where
     SpecifiedValueInfo,
     ToComputedValue,
     ToCss,
+    ToShmem,
 )]
 pub struct VariationValue<Number> {
     /// A four-character tag, packed into a u32 (one byte per character).
@@ -67,7 +70,9 @@ pub struct VariationValue<Number> {
 
 /// A value both for font-variation-settings and font-feature-settings.
 #[css(comma)]
-#[derive(Clone, Debug, Eq, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss)]
+#[derive(
+    Clone, Debug, Eq, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss, ToShmem,
+)]
 pub struct FontSettings<T>(#[css(if_empty = "normal", iterable)] pub Box<[T]>);
 
 impl<T> FontSettings<T> {
@@ -103,7 +108,9 @@ impl<T: Parse> Parse for FontSettings<T> {
 ///   https://drafts.csswg.org/css-fonts-4/#font-variation-settings-def
 ///   https://drafts.csswg.org/css-fonts-4/#descdef-font-face-font-feature-settings
 ///
-#[derive(Clone, Copy, Debug, Eq, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue)]
+#[derive(
+    Clone, Copy, Debug, Eq, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToShmem,
+)]
 pub struct FontTag(pub u32);
 
 impl ToCss for FontTag {
@@ -149,6 +156,7 @@ impl Parse for FontTag {
     ToAnimatedValue,
     ToAnimatedZero,
     ToCss,
+    ToShmem,
 )]
 /// Additional information for keyword-derived font sizes.
 pub struct KeywordInfo<Length> {
@@ -205,6 +213,7 @@ impl<L> SpecifiedValueInfo for KeywordInfo<L> {
     ToAnimatedValue,
     ToAnimatedZero,
     ToCss,
+    ToShmem,
 )]
 #[allow(missing_docs)]
 pub enum KeywordSize {
@@ -254,6 +263,7 @@ impl Default for KeywordSize {
     SpecifiedValueInfo,
     ToAnimatedValue,
     ToAnimatedZero,
+    ToShmem,
 )]
 pub enum FontStyle<Angle> {
     #[animation(error)]
diff --git a/components/style/values/generics/gecko.rs b/components/style/values/generics/gecko.rs
index fb84fdf4acc..5a91f2e14f4 100644
--- a/components/style/values/generics/gecko.rs
+++ b/components/style/values/generics/gecko.rs
@@ -7,7 +7,7 @@
 
 /// A generic value for scroll snap points.
 #[cfg_attr(feature = "gecko", derive(MallocSizeOf))]
-#[derive(Clone, Copy, Debug, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss)]
+#[derive(Clone, Copy, Debug, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss, ToShmem)]
 pub enum ScrollSnapPoint<LengthPercentage> {
     /// `none`
     None,
diff --git a/components/style/values/generics/grid.rs b/components/style/values/generics/grid.rs
index 6650996c794..a3a94d3eaf5 100644
--- a/components/style/values/generics/grid.rs
+++ b/components/style/values/generics/grid.rs
@@ -18,7 +18,9 @@ use style_traits::{CssWriter, ParseError, StyleParseErrorKind, ToCss};
 /// A `<grid-line>` type.
 ///
 /// <https://drafts.csswg.org/css-grid/#typedef-grid-row-start-grid-line>
-#[derive(Clone, Debug, Default, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue)]
+#[derive(
+    Clone, Debug, Default, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToShmem,
+)]
 pub struct GridLine<Integer> {
     /// Flag to check whether it's a `span` keyword.
     pub is_span: bool,
@@ -162,6 +164,7 @@ impl Parse for GridLine<specified::Integer> {
     SpecifiedValueInfo,
     ToComputedValue,
     ToCss,
+    ToShmem,
 )]
 pub enum TrackKeyword {
     Auto,
@@ -174,7 +177,15 @@ pub enum TrackKeyword {
 ///
 /// <https://drafts.csswg.org/css-grid/#typedef-track-breadth>
 #[derive(
-    Animate, Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss,
+    Animate,
+    Clone,
+    Debug,
+    MallocSizeOf,
+    PartialEq,
+    SpecifiedValueInfo,
+    ToComputedValue,
+    ToCss,
+    ToShmem,
 )]
 pub enum TrackBreadth<L> {
     /// The generic type is almost always a non-negative `<length-percentage>`
@@ -200,7 +211,7 @@ impl<L> TrackBreadth<L> {
 /// generic only to avoid code bloat. It only takes `<length-percentage>`
 ///
 /// <https://drafts.csswg.org/css-grid/#typedef-track-size>
-#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo)]
+#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToShmem)]
 pub enum TrackSize<L> {
     /// A flexible `<track-breadth>`
     Breadth(TrackBreadth<L>),
@@ -358,7 +369,7 @@ where
 /// The initial argument of the `repeat` function.
 ///
 /// <https://drafts.csswg.org/css-grid/#typedef-track-repeat>
-#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, ToComputedValue, ToCss)]
+#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, ToComputedValue, ToCss, ToShmem)]
 pub enum RepeatCount<Integer> {
     /// A positive integer. This is allowed only for `<track-repeat>` and `<fixed-repeat>`
     Number(Integer),
@@ -393,7 +404,7 @@ impl Parse for RepeatCount<specified::Integer> {
 ///
 /// It can also hold `repeat()` function parameters, which expands into the respective
 /// values in its computed form.
-#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue)]
+#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToShmem)]
 #[css(function = "repeat")]
 pub struct TrackRepeat<L, I> {
     /// The number of times for the value to be repeated (could also be `auto-fit` or `auto-fill`)
@@ -482,7 +493,15 @@ impl<L: Clone> TrackRepeat<L, specified::Integer> {
 
 /// Track list values. Can be <track-size> or <track-repeat>
 #[derive(
-    Animate, Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss,
+    Animate,
+    Clone,
+    Debug,
+    MallocSizeOf,
+    PartialEq,
+    SpecifiedValueInfo,
+    ToComputedValue,
+    ToCss,
+    ToShmem,
 )]
 pub enum TrackListValue<LengthPercentage, Integer> {
     /// A <track-size> value.
@@ -494,7 +513,7 @@ pub enum TrackListValue<LengthPercentage, Integer> {
 /// The type of a `<track-list>` as determined during parsing.
 ///
 /// <https://drafts.csswg.org/css-grid/#typedef-track-list>
-#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, ToComputedValue)]
+#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, ToComputedValue, ToShmem)]
 pub enum TrackListType {
     /// [`<auto-track-list>`](https://drafts.csswg.org/css-grid/#typedef-auto-track-list)
     ///
@@ -516,7 +535,7 @@ pub enum TrackListType {
 /// A grid `<track-list>` type.
 ///
 /// <https://drafts.csswg.org/css-grid/#typedef-track-list>
-#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo)]
+#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToShmem)]
 pub struct TrackList<LengthPercentage, Integer> {
     /// The type of this `<track-list>` (auto, explicit or general).
     ///
@@ -589,7 +608,9 @@ impl<L: ToCss, I: ToCss> ToCss for TrackList<L, I> {
 ///
 /// `subgrid [ <line-names> | repeat(<positive-integer> | auto-fill, <line-names>+) ]+`
 /// Old spec: https://www.w3.org/TR/2015/WD-css-grid-1-20150917/#typedef-line-name-list
-#[derive(Clone, Debug, Default, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue)]
+#[derive(
+    Clone, Debug, Default, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToShmem,
+)]
 pub struct LineNameList {
     /// The optional `<line-name-list>`
     pub names: Box<[Box<[CustomIdent]>]>,
@@ -695,7 +716,15 @@ impl ToCss for LineNameList {
 /// Subgrid deferred to Level 2 spec due to lack of implementation.
 /// But it's implemented in gecko, so we have to as well.
 #[derive(
-    Animate, Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss,
+    Animate,
+    Clone,
+    Debug,
+    MallocSizeOf,
+    PartialEq,
+    SpecifiedValueInfo,
+    ToComputedValue,
+    ToCss,
+    ToShmem,
 )]
 pub enum GridTemplateComponent<L, I> {
     /// `none` value.
@@ -704,6 +733,7 @@ pub enum GridTemplateComponent<L, I> {
     TrackList(
         #[animation(field_bound)]
         #[compute(field_bound)]
+        #[shmem(field_bound)]
         TrackList<L, I>,
     ),
     /// A `subgrid <line-name-list>?`
diff --git a/components/style/values/generics/image.rs b/components/style/values/generics/image.rs
index 44ff903b4f4..3f8b4f76f58 100644
--- a/components/style/values/generics/image.rs
+++ b/components/style/values/generics/image.rs
@@ -16,7 +16,7 @@ use style_traits::{CssWriter, ToCss};
 /// An [image].
 ///
 /// [image]: https://drafts.csswg.org/css-images/#image-values
-#[derive(Clone, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue)]
+#[derive(Clone, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToShmem)]
 pub enum Image<Gradient, MozImageRect, ImageUrl> {
     /// A `<url()>` image.
     Url(ImageUrl),
@@ -36,7 +36,7 @@ pub enum Image<Gradient, MozImageRect, ImageUrl> {
 
 /// A CSS gradient.
 /// <https://drafts.csswg.org/css-images/#gradients>
-#[derive(Clone, Debug, MallocSizeOf, PartialEq, ToComputedValue)]
+#[derive(Clone, Debug, MallocSizeOf, PartialEq, ToComputedValue, ToShmem)]
 pub struct Gradient<LineDirection, Length, LengthPercentage, Position, Color, Angle> {
     /// Gradients can be linear or radial.
     pub kind: GradientKind<LineDirection, Length, LengthPercentage, Position, Angle>,
@@ -48,7 +48,7 @@ pub struct Gradient<LineDirection, Length, LengthPercentage, Position, Color, An
     pub compat_mode: CompatMode,
 }
 
-#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, ToComputedValue)]
+#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, ToComputedValue, ToShmem)]
 /// Whether we used the modern notation or the compatibility `-webkit`, `-moz` prefixes.
 pub enum CompatMode {
     /// Modern syntax.
@@ -60,7 +60,7 @@ pub enum CompatMode {
 }
 
 /// A gradient kind.
-#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, ToComputedValue)]
+#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, ToComputedValue, ToShmem)]
 pub enum GradientKind<LineDirection, Length, LengthPercentage, Position, Angle> {
     /// A linear gradient.
     Linear(LineDirection),
@@ -73,7 +73,7 @@ pub enum GradientKind<LineDirection, Length, LengthPercentage, Position, Angle>
 }
 
 /// A radial gradient's ending shape.
-#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, ToComputedValue, ToCss)]
+#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, ToComputedValue, ToCss, ToShmem)]
 pub enum EndingShape<Length, LengthPercentage> {
     /// A circular gradient.
     Circle(Circle<Length>),
@@ -82,7 +82,7 @@ pub enum EndingShape<Length, LengthPercentage> {
 }
 
 /// A circle shape.
-#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, ToComputedValue)]
+#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, ToComputedValue, ToShmem)]
 pub enum Circle<Length> {
     /// A circle radius.
     Radius(Length),
@@ -91,7 +91,7 @@ pub enum Circle<Length> {
 }
 
 /// An ellipse shape.
-#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, ToComputedValue, ToCss)]
+#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, ToComputedValue, ToCss, ToShmem)]
 pub enum Ellipse<LengthPercentage> {
     /// An ellipse pair of radii.
     Radii(LengthPercentage, LengthPercentage),
@@ -102,7 +102,9 @@ pub enum Ellipse<LengthPercentage> {
 /// <https://drafts.csswg.org/css-images/#typedef-extent-keyword>
 #[allow(missing_docs)]
 #[cfg_attr(feature = "servo", derive(Deserialize, Serialize))]
-#[derive(Clone, Copy, Debug, Eq, MallocSizeOf, Parse, PartialEq, ToComputedValue, ToCss)]
+#[derive(
+    Clone, Copy, Debug, Eq, MallocSizeOf, Parse, PartialEq, ToComputedValue, ToCss, ToShmem,
+)]
 pub enum ShapeExtent {
     ClosestSide,
     FarthestSide,
@@ -114,7 +116,7 @@ pub enum ShapeExtent {
 
 /// A gradient item.
 /// <https://drafts.csswg.org/css-images-4/#color-stop-syntax>
-#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, ToComputedValue, ToCss)]
+#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, ToComputedValue, ToCss, ToShmem)]
 pub enum GradientItem<Color, LengthPercentage> {
     /// A color stop.
     ColorStop(ColorStop<Color, LengthPercentage>),
@@ -124,7 +126,7 @@ pub enum GradientItem<Color, LengthPercentage> {
 
 /// A color stop.
 /// <https://drafts.csswg.org/css-images/#typedef-color-stop-list>
-#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, ToComputedValue, ToCss)]
+#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, ToComputedValue, ToCss, ToShmem)]
 pub struct ColorStop<Color, LengthPercentage> {
     /// The color of this stop.
     pub color: Color,
@@ -167,7 +169,9 @@ impl ToCss for PaintWorklet {
 /// `-moz-image-rect(<uri>, top, right, bottom, left);`
 #[allow(missing_docs)]
 #[css(comma, function)]
-#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss)]
+#[derive(
+    Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss, ToShmem,
+)]
 pub struct MozImageRect<NumberOrPercentage, MozImageRectUrl> {
     pub url: MozImageRectUrl,
     pub top: NumberOrPercentage,
diff --git a/components/style/values/generics/length.rs b/components/style/values/generics/length.rs
index 076a02a4a0f..e805c1b0cd7 100644
--- a/components/style/values/generics/length.rs
+++ b/components/style/values/generics/length.rs
@@ -26,6 +26,7 @@ use style_traits::ParseError;
     ToAnimatedZero,
     ToComputedValue,
     ToCss,
+    ToShmem,
 )]
 #[repr(C, u8)]
 pub enum GenericLengthPercentageOrAuto<LengthPercent> {
@@ -109,6 +110,7 @@ impl<LengthPercentage: Parse> Parse for LengthPercentageOrAuto<LengthPercentage>
     ToAnimatedZero,
     ToComputedValue,
     ToCss,
+    ToShmem,
 )]
 #[repr(C, u8)]
 pub enum GenericSize<LengthPercent> {
@@ -150,6 +152,7 @@ impl<LengthPercentage> Size<LengthPercentage> {
     ToAnimatedZero,
     ToComputedValue,
     ToCss,
+    ToShmem,
 )]
 #[repr(C, u8)]
 pub enum GenericMaxSize<LengthPercent> {
@@ -185,6 +188,7 @@ impl<LengthPercentage> MaxSize<LengthPercentage> {
     ToAnimatedZero,
     ToComputedValue,
     ToCss,
+    ToShmem,
 )]
 #[repr(C, u8)]
 pub enum GenericLengthOrNumber<L, N> {
diff --git a/components/style/values/generics/mod.rs b/components/style/values/generics/mod.rs
index e054db7281f..44b85931661 100644
--- a/components/style/values/generics/mod.rs
+++ b/components/style/values/generics/mod.rs
@@ -43,7 +43,9 @@ pub mod url;
 // https://drafts.csswg.org/css-counter-styles/#typedef-symbols-type
 #[allow(missing_docs)]
 #[cfg_attr(feature = "servo", derive(Deserialize, Serialize))]
-#[derive(Clone, Copy, Debug, Eq, MallocSizeOf, Parse, PartialEq, ToComputedValue, ToCss)]
+#[derive(
+    Clone, Copy, Debug, Eq, MallocSizeOf, Parse, PartialEq, ToComputedValue, ToCss, ToShmem,
+)]
 pub enum SymbolsType {
     Cyclic,
     Numeric,
@@ -85,7 +87,7 @@ impl SymbolsType {
 /// Since wherever <counter-style> is used, 'none' is a valid value as
 /// well, we combine them into one type to make code simpler.
 #[cfg_attr(feature = "gecko", derive(MallocSizeOf))]
-#[derive(Clone, Debug, Eq, PartialEq, ToComputedValue, ToCss)]
+#[derive(Clone, Debug, Eq, PartialEq, ToComputedValue, ToCss, ToShmem)]
 pub enum CounterStyleOrNone {
     /// `none`
     None,
@@ -173,6 +175,7 @@ impl SpecifiedValueInfo for CounterStyleOrNone {
     ToAnimatedZero,
     ToComputedValue,
     ToCss,
+    ToShmem,
 )]
 #[repr(transparent)]
 pub struct NonNegative<T>(pub T);
@@ -210,6 +213,7 @@ impl<T: Zero> Zero for NonNegative<T> {
     ToAnimatedZero,
     ToComputedValue,
     ToCss,
+    ToShmem,
 )]
 pub struct GreaterThanOrEqualToOne<T>(pub T);
 
@@ -227,6 +231,7 @@ pub struct GreaterThanOrEqualToOne<T>(pub T);
     ToAnimatedZero,
     ToComputedValue,
     ToCss,
+    ToShmem,
 )]
 #[css(function = "rect", comma)]
 pub struct ClipRect<LengthOrAuto> {
diff --git a/components/style/values/generics/position.rs b/components/style/values/generics/position.rs
index 34034b7d5b7..59a86c4b43f 100644
--- a/components/style/values/generics/position.rs
+++ b/components/style/values/generics/position.rs
@@ -18,6 +18,7 @@
     ToAnimatedValue,
     ToAnimatedZero,
     ToComputedValue,
+    ToShmem,
 )]
 #[repr(C)]
 pub struct GenericPosition<H, V> {
@@ -53,6 +54,7 @@ impl<H, V> Position<H, V> {
     ToAnimatedZero,
     ToComputedValue,
     ToCss,
+    ToShmem,
 )]
 #[repr(C, u8)]
 pub enum GenericZIndex<I> {
diff --git a/components/style/values/generics/rect.rs b/components/style/values/generics/rect.rs
index de7237e694d..43f7b34bb06 100644
--- a/components/style/values/generics/rect.rs
+++ b/components/style/values/generics/rect.rs
@@ -22,6 +22,7 @@ use style_traits::{CssWriter, ParseError, ToCss};
     SpecifiedValueInfo,
     ToAnimatedValue,
     ToComputedValue,
+    ToShmem,
 )]
 #[repr(C)]
 pub struct Rect<T>(pub T, pub T, pub T, pub T);
diff --git a/components/style/values/generics/size.rs b/components/style/values/generics/size.rs
index 96e0003128f..99cf966de73 100644
--- a/components/style/values/generics/size.rs
+++ b/components/style/values/generics/size.rs
@@ -24,6 +24,7 @@ use style_traits::{CssWriter, ParseError, ToCss};
     ToAnimatedZero,
     ToAnimatedValue,
     ToComputedValue,
+    ToShmem,
 )]
 #[allow(missing_docs)]
 #[repr(C)]
diff --git a/components/style/values/generics/svg.rs b/components/style/values/generics/svg.rs
index 6a4d2411e76..d385b570291 100644
--- a/components/style/values/generics/svg.rs
+++ b/components/style/values/generics/svg.rs
@@ -24,6 +24,7 @@ use style_traits::{ParseError, StyleParseErrorKind};
     ToAnimatedValue,
     ToComputedValue,
     ToCss,
+    ToShmem,
 )]
 pub struct SVGPaint<ColorType, UrlPaintServer> {
     /// The paint source
@@ -50,6 +51,7 @@ pub struct SVGPaint<ColorType, UrlPaintServer> {
     ToAnimatedZero,
     ToComputedValue,
     ToCss,
+    ToShmem,
 )]
 pub enum SVGPaintKind<ColorType, UrlPaintServer> {
     /// `none`
@@ -142,6 +144,7 @@ impl<ColorType: Parse, UrlPaintServer: Parse> Parse for SVGPaint<ColorType, UrlP
     ToAnimatedZero,
     ToComputedValue,
     ToCss,
+    ToShmem,
 )]
 pub enum SVGLength<L> {
     /// `<length> | <percentage> | <number>`
@@ -162,6 +165,7 @@ pub enum SVGLength<L> {
     ToAnimatedZero,
     ToComputedValue,
     ToCss,
+    ToShmem,
 )]
 pub enum SVGStrokeDashArray<L> {
     /// `[ <length> | <percentage> | <number> ]#`
@@ -186,6 +190,7 @@ pub enum SVGStrokeDashArray<L> {
     ToAnimatedZero,
     ToComputedValue,
     ToCss,
+    ToShmem,
 )]
 pub enum SVGOpacity<OpacityType> {
     /// `<opacity-value>`
diff --git a/components/style/values/generics/text.rs b/components/style/values/generics/text.rs
index 509491c8624..47abc958e65 100644
--- a/components/style/values/generics/text.rs
+++ b/components/style/values/generics/text.rs
@@ -11,7 +11,15 @@ use style_traits::ParseError;
 
 /// A generic value for the `initial-letter` property.
 #[derive(
-    Clone, Copy, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss,
+    Clone,
+    Copy,
+    Debug,
+    MallocSizeOf,
+    PartialEq,
+    SpecifiedValueInfo,
+    ToComputedValue,
+    ToCss,
+    ToShmem,
 )]
 pub enum InitialLetter<Number, Integer> {
     /// `normal`
@@ -29,7 +37,9 @@ impl<N, I> InitialLetter<N, I> {
 }
 
 /// A generic spacing value for the `letter-spacing` and `word-spacing` properties.
-#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToCss)]
+#[derive(
+    Clone, Copy, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToCss, ToShmem,
+)]
 pub enum Spacing<Value> {
     /// `normal`
     Normal,
@@ -81,6 +91,7 @@ fn line_height_moz_block_height_enabled(context: &ParserContext) -> bool {
     SpecifiedValueInfo,
     ToAnimatedValue,
     ToCss,
+    ToShmem,
     Parse,
 )]
 #[repr(C, u8)]
diff --git a/components/style/values/generics/transform.rs b/components/style/values/generics/transform.rs
index 3e091162b2e..530f2b996ca 100644
--- a/components/style/values/generics/transform.rs
+++ b/components/style/values/generics/transform.rs
@@ -19,7 +19,15 @@ use style_traits::{CssWriter, ToCss};
 /// A generic 2D transformation matrix.
 #[allow(missing_docs)]
 #[derive(
-    Clone, Copy, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss,
+    Clone,
+    Copy,
+    Debug,
+    MallocSizeOf,
+    PartialEq,
+    SpecifiedValueInfo,
+    ToComputedValue,
+    ToCss,
+    ToShmem,
 )]
 #[css(comma, function)]
 pub struct Matrix<T> {
@@ -35,7 +43,7 @@ pub struct Matrix<T> {
 #[cfg_attr(rustfmt, rustfmt_skip)]
 #[css(comma, function = "matrix3d")]
 #[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo,
-         ToComputedValue, ToCss)]
+         ToComputedValue, ToCss, ToShmem)]
 pub struct Matrix3D<T> {
     pub m11: T, pub m12: T, pub m13: T, pub m14: T,
     pub m21: T, pub m22: T, pub m23: T, pub m24: T,
@@ -82,6 +90,7 @@ impl<T: Into<f64>> From<Matrix3D<T>> for Transform3D<f64> {
     ToAnimatedZero,
     ToComputedValue,
     ToCss,
+    ToShmem,
 )]
 #[repr(C)]
 pub struct GenericTransformOrigin<H, V, Depth> {
@@ -110,7 +119,9 @@ fn is_same<N: PartialEq>(x: &N, y: &N) -> bool {
     x == y
 }
 
-#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss)]
+#[derive(
+    Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss, ToShmem,
+)]
 /// A single operation in the list of a `transform` value
 pub enum TransformOperation<Angle, Number, Length, Integer, LengthPercentage>
 where
@@ -215,7 +226,9 @@ where
     },
 }
 
-#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss)]
+#[derive(
+    Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss, ToShmem,
+)]
 /// A value of the `transform` property
 pub struct Transform<T>(#[css(if_empty = "none", iterable)] pub Vec<T>);
 
@@ -537,7 +550,15 @@ pub fn get_normalized_vector_and_angle<T: Zero>(
 }
 
 #[derive(
-    Clone, Copy, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToAnimatedZero, ToComputedValue,
+    Clone,
+    Copy,
+    Debug,
+    MallocSizeOf,
+    PartialEq,
+    SpecifiedValueInfo,
+    ToAnimatedZero,
+    ToComputedValue,
+    ToShmem,
 )]
 /// A value of the `Rotate` property
 ///
@@ -599,7 +620,15 @@ where
 }
 
 #[derive(
-    Clone, Copy, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToAnimatedZero, ToComputedValue,
+    Clone,
+    Copy,
+    Debug,
+    MallocSizeOf,
+    PartialEq,
+    SpecifiedValueInfo,
+    ToAnimatedZero,
+    ToComputedValue,
+    ToShmem,
 )]
 /// A value of the `Scale` property
 ///
@@ -648,6 +677,7 @@ impl<Number: ToCss + PartialEq> ToCss for Scale<Number> {
     ToAnimatedZero,
     ToComputedValue,
     ToCss,
+    ToShmem,
 )]
 /// A value of the `translate` property
 ///
@@ -680,7 +710,16 @@ where
 
 #[allow(missing_docs)]
 #[derive(
-    Clone, Copy, Debug, MallocSizeOf, Parse, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss,
+    Clone,
+    Copy,
+    Debug,
+    MallocSizeOf,
+    Parse,
+    PartialEq,
+    SpecifiedValueInfo,
+    ToComputedValue,
+    ToCss,
+    ToShmem,
 )]
 pub enum TransformStyle {
     #[cfg(feature = "servo")]
diff --git a/components/style/values/generics/ui.rs b/components/style/values/generics/ui.rs
index 2a984b915a0..e6eed9afaa5 100644
--- a/components/style/values/generics/ui.rs
+++ b/components/style/values/generics/ui.rs
@@ -11,7 +11,7 @@ use values::specified::ui::CursorKind;
 /// A generic value for the `cursor` property.
 ///
 /// https://drafts.csswg.org/css-ui/#cursor
-#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue)]
+#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToShmem)]
 pub struct Cursor<Image> {
     /// The parsed images for the cursor.
     pub images: Box<[Image]>,
@@ -44,7 +44,7 @@ impl<Image: ToCss> ToCss for Cursor<Image> {
 }
 
 /// A generic value for item of `image cursors`.
-#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue)]
+#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToShmem)]
 pub struct CursorImage<ImageUrl, Number> {
     /// The url to parse images from.
     pub url: ImageUrl,
@@ -84,6 +84,7 @@ impl<ImageUrl: ToCss, Number: ToCss> ToCss for CursorImage<ImageUrl, Number> {
     ToAnimatedZero,
     ToComputedValue,
     ToCss,
+    ToShmem,
 )]
 pub enum ScrollbarColor<Color> {
     /// `auto`
diff --git a/components/style/values/generics/url.rs b/components/style/values/generics/url.rs
index 80fa48ba882..d86800dbcd4 100644
--- a/components/style/values/generics/url.rs
+++ b/components/style/values/generics/url.rs
@@ -18,6 +18,7 @@
     ToAnimatedZero,
     ToComputedValue,
     ToCss,
+    ToShmem,
 )]
 pub enum UrlOrNone<Url> {
     /// `none`
diff --git a/components/style/values/mod.rs b/components/style/values/mod.rs
index b555598317b..4665257a0c6 100644
--- a/components/style/values/mod.rs
+++ b/components/style/values/mod.rs
@@ -134,6 +134,7 @@ impl Parse for Impossible {
     ToAnimatedZero,
     ToComputedValue,
     ToCss,
+    ToShmem,
 )]
 pub enum Either<A, B> {
     /// The first value.
@@ -152,7 +153,9 @@ impl<A: Debug, B: Debug> Debug for Either<A, B> {
 }
 
 /// <https://drafts.csswg.org/css-values-4/#custom-idents>
-#[derive(Clone, Debug, Eq, Hash, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue)]
+#[derive(
+    Clone, Debug, Eq, Hash, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToShmem,
+)]
 pub struct CustomIdent(pub Atom);
 
 impl CustomIdent {
@@ -189,7 +192,7 @@ impl ToCss for CustomIdent {
 }
 
 /// <https://drafts.csswg.org/css-animations/#typedef-keyframes-name>
-#[derive(Clone, Debug, MallocSizeOf, SpecifiedValueInfo, ToComputedValue)]
+#[derive(Clone, Debug, MallocSizeOf, SpecifiedValueInfo, ToComputedValue, ToShmem)]
 pub enum KeyframesName {
     /// <custom-ident>
     Ident(CustomIdent),
diff --git a/components/style/values/specified/align.rs b/components/style/values/specified/align.rs
index befeaa2ee6f..e6ba57b6322 100644
--- a/components/style/values/specified/align.rs
+++ b/components/style/values/specified/align.rs
@@ -16,7 +16,7 @@ bitflags! {
     /// Constants shared by multiple CSS Box Alignment properties
     ///
     /// These constants match Gecko's `NS_STYLE_ALIGN_*` constants.
-    #[derive(MallocSizeOf, ToComputedValue)]
+    #[derive(MallocSizeOf, ToComputedValue, ToShmem)]
     pub struct AlignFlags: u8 {
         // Enumeration stored in the lower 5 bits:
         /// 'auto'
@@ -134,7 +134,7 @@ pub enum AxisDirection {
 /// Shared value for the `align-content` and `justify-content` properties.
 ///
 /// <https://drafts.csswg.org/css-align/#content-distribution>
-#[derive(Clone, Copy, Debug, Eq, MallocSizeOf, PartialEq, ToComputedValue, ToCss)]
+#[derive(Clone, Copy, Debug, Eq, MallocSizeOf, PartialEq, ToComputedValue, ToCss, ToShmem)]
 #[cfg_attr(feature = "servo", derive(Deserialize, Serialize))]
 pub struct ContentDistribution {
     primary: AlignFlags,
@@ -247,7 +247,7 @@ impl ContentDistribution {
 /// Value for the `align-content` property.
 ///
 /// <https://drafts.csswg.org/css-align/#propdef-align-content>
-#[derive(Clone, Copy, Debug, Eq, MallocSizeOf, PartialEq, ToComputedValue, ToCss)]
+#[derive(Clone, Copy, Debug, Eq, MallocSizeOf, PartialEq, ToComputedValue, ToCss, ToShmem)]
 pub struct AlignContent(pub ContentDistribution);
 
 impl Parse for AlignContent {
@@ -287,7 +287,7 @@ impl From<AlignContent> for u16 {
 /// Value for the `justify-content` property.
 ///
 /// <https://drafts.csswg.org/css-align/#propdef-justify-content>
-#[derive(Clone, Copy, Debug, Eq, MallocSizeOf, PartialEq, ToComputedValue, ToCss)]
+#[derive(Clone, Copy, Debug, Eq, MallocSizeOf, PartialEq, ToComputedValue, ToCss, ToShmem)]
 pub struct JustifyContent(pub ContentDistribution);
 
 impl Parse for JustifyContent {
@@ -325,7 +325,7 @@ impl From<JustifyContent> for u16 {
 }
 
 /// <https://drafts.csswg.org/css-align/#self-alignment>
-#[derive(Clone, Copy, Debug, Eq, MallocSizeOf, PartialEq, ToComputedValue, ToCss)]
+#[derive(Clone, Copy, Debug, Eq, MallocSizeOf, PartialEq, ToComputedValue, ToCss, ToShmem)]
 pub struct SelfAlignment(pub AlignFlags);
 
 impl SelfAlignment {
@@ -385,7 +385,7 @@ impl SelfAlignment {
 /// The specified value of the align-self property.
 ///
 /// <https://drafts.csswg.org/css-align/#propdef-align-self>
-#[derive(Clone, Copy, Debug, Eq, MallocSizeOf, PartialEq, ToComputedValue, ToCss)]
+#[derive(Clone, Copy, Debug, Eq, MallocSizeOf, PartialEq, ToComputedValue, ToCss, ToShmem)]
 pub struct AlignSelf(pub SelfAlignment);
 
 impl Parse for AlignSelf {
@@ -423,7 +423,7 @@ impl From<AlignSelf> for u8 {
 /// The specified value of the justify-self property.
 ///
 /// <https://drafts.csswg.org/css-align/#propdef-justify-self>
-#[derive(Clone, Copy, Debug, Eq, MallocSizeOf, PartialEq, ToComputedValue, ToCss)]
+#[derive(Clone, Copy, Debug, Eq, MallocSizeOf, PartialEq, ToComputedValue, ToCss, ToShmem)]
 pub struct JustifySelf(pub SelfAlignment);
 
 impl Parse for JustifySelf {
@@ -461,7 +461,7 @@ impl From<JustifySelf> for u8 {
 /// Value of the `align-items` property
 ///
 /// <https://drafts.csswg.org/css-align/#propdef-align-items>
-#[derive(Clone, Copy, Debug, Eq, MallocSizeOf, PartialEq, ToComputedValue, ToCss)]
+#[derive(Clone, Copy, Debug, Eq, MallocSizeOf, PartialEq, ToComputedValue, ToCss, ToShmem)]
 pub struct AlignItems(pub AlignFlags);
 
 impl AlignItems {
@@ -512,7 +512,7 @@ impl SpecifiedValueInfo for AlignItems {
 /// Value of the `justify-items` property
 ///
 /// <https://drafts.csswg.org/css-align/#justify-items-property>
-#[derive(Clone, Copy, Debug, Eq, MallocSizeOf, PartialEq, ToCss)]
+#[derive(Clone, Copy, Debug, Eq, MallocSizeOf, PartialEq, ToCss, ToShmem)]
 pub struct JustifyItems(pub AlignFlags);
 
 impl JustifyItems {
diff --git a/components/style/values/specified/angle.rs b/components/style/values/specified/angle.rs
index 01eb58368b9..47c1a60772b 100644
--- a/components/style/values/specified/angle.rs
+++ b/components/style/values/specified/angle.rs
@@ -17,7 +17,7 @@ use style_traits::{CssWriter, ParseError, SpecifiedValueInfo, ToCss};
 
 /// A specified angle dimension.
 #[cfg_attr(feature = "servo", derive(Deserialize, Serialize))]
-#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, PartialOrd, ToCss)]
+#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, PartialOrd, ToCss, ToShmem)]
 pub enum AngleDimension {
     /// An angle with degree unit.
     #[css(dimension)]
@@ -68,7 +68,7 @@ impl AngleDimension {
 /// A specified Angle value, which is just the angle dimension, plus whether it
 /// was specified as `calc()` or not.
 #[cfg_attr(feature = "servo", derive(Deserialize, Serialize))]
-#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq)]
+#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, ToShmem)]
 pub struct Angle {
     value: AngleDimension,
     was_calc: bool,
diff --git a/components/style/values/specified/background.rs b/components/style/values/specified/background.rs
index a1605e977eb..6982326b945 100644
--- a/components/style/values/specified/background.rs
+++ b/components/style/values/specified/background.rs
@@ -47,6 +47,7 @@ impl Parse for BackgroundSize {
     SpecifiedValueInfo,
     ToComputedValue,
     ToCss,
+    ToShmem,
 )]
 #[allow(missing_docs)]
 #[value_info(other_values = "repeat-x,repeat-y")]
@@ -62,7 +63,7 @@ pub enum BackgroundRepeatKeyword {
 /// axes.
 ///
 /// https://drafts.csswg.org/css-backgrounds/#the-background-repeat
-#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue)]
+#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToShmem)]
 pub struct BackgroundRepeat(pub BackgroundRepeatKeyword, pub BackgroundRepeatKeyword);
 
 impl BackgroundRepeat {
diff --git a/components/style/values/specified/border.rs b/components/style/values/specified/border.rs
index d0ef8126482..415c104a12d 100644
--- a/components/style/values/specified/border.rs
+++ b/components/style/values/specified/border.rs
@@ -40,6 +40,7 @@ use style_traits::{CssWriter, ParseError, ToCss};
     SpecifiedValueInfo,
     ToComputedValue,
     ToCss,
+    ToShmem,
 )]
 #[repr(u8)]
 pub enum BorderStyle {
@@ -64,7 +65,7 @@ impl BorderStyle {
 }
 
 /// A specified value for a single side of the `border-width` property.
-#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToCss)]
+#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToCss, ToShmem)]
 pub enum BorderSideWidth {
     /// `thin`
     Thin,
@@ -249,7 +250,9 @@ impl Parse for BorderSpacing {
 /// A single border-image-repeat keyword.
 #[allow(missing_docs)]
 #[cfg_attr(feature = "servo", derive(Deserialize, Serialize))]
-#[derive(Clone, Copy, Debug, Eq, MallocSizeOf, Parse, PartialEq, SpecifiedValueInfo, ToCss)]
+#[derive(
+    Clone, Copy, Debug, Eq, MallocSizeOf, Parse, PartialEq, SpecifiedValueInfo, ToCss, ToShmem,
+)]
 pub enum BorderImageRepeatKeyword {
     Stretch,
     Repeat,
@@ -260,7 +263,9 @@ pub enum BorderImageRepeatKeyword {
 /// The specified value for the `border-image-repeat` property.
 ///
 /// https://drafts.csswg.org/css-backgrounds/#the-border-image-repeat
-#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue)]
+#[derive(
+    Clone, Copy, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToShmem,
+)]
 pub struct BorderImageRepeat(pub BorderImageRepeatKeyword, pub BorderImageRepeatKeyword);
 
 impl ToCss for BorderImageRepeat {
diff --git a/components/style/values/specified/box.rs b/components/style/values/specified/box.rs
index 11ab02f045f..6d69c453845 100644
--- a/components/style/values/specified/box.rs
+++ b/components/style/values/specified/box.rs
@@ -61,6 +61,7 @@ fn moz_box_display_values_enabled(context: &ParserContext) -> bool {
     SpecifiedValueInfo,
     ToComputedValue,
     ToCss,
+    ToShmem,
 )]
 #[cfg_attr(feature = "servo", derive(Deserialize, Serialize))]
 #[repr(u8)]
@@ -324,7 +325,9 @@ impl AnimationIterationCount {
 }
 
 /// A value for the `animation-name` property.
-#[derive(Clone, Debug, Eq, Hash, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue)]
+#[derive(
+    Clone, Debug, Eq, Hash, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToShmem,
+)]
 #[value_info(other_values = "none")]
 pub struct AnimationName(pub Option<KeyframesName>);
 
@@ -379,6 +382,7 @@ impl Parse for AnimationName {
     SpecifiedValueInfo,
     ToComputedValue,
     ToCss,
+    ToShmem,
 )]
 #[repr(u8)]
 pub enum ScrollSnapType {
@@ -402,6 +406,7 @@ pub enum ScrollSnapType {
     SpecifiedValueInfo,
     ToComputedValue,
     ToCss,
+    ToShmem,
 )]
 #[repr(u8)]
 pub enum ScrollSnapAlignKeyword {
@@ -413,7 +418,9 @@ pub enum ScrollSnapAlignKeyword {
 
 /// https://drafts.csswg.org/css-scroll-snap-1/#scroll-snap-align
 #[allow(missing_docs)]
-#[derive(Clone, Copy, Debug, Eq, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue)]
+#[derive(
+    Clone, Copy, Debug, Eq, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToShmem,
+)]
 #[repr(C)]
 pub struct ScrollSnapAlign {
     block: ScrollSnapAlignKeyword,
@@ -470,6 +477,7 @@ impl ToCss for ScrollSnapAlign {
     SpecifiedValueInfo,
     ToComputedValue,
     ToCss,
+    ToShmem,
 )]
 #[repr(u8)]
 pub enum OverscrollBehavior {
@@ -491,6 +499,7 @@ pub enum OverscrollBehavior {
     SpecifiedValueInfo,
     ToComputedValue,
     ToCss,
+    ToShmem,
 )]
 #[repr(u8)]
 pub enum OverflowAnchor {
@@ -511,6 +520,7 @@ pub enum OverflowAnchor {
     SpecifiedValueInfo,
     ToComputedValue,
     ToCss,
+    ToShmem,
 )]
 #[repr(u8)]
 pub enum OverflowClipBox {
@@ -518,7 +528,9 @@ pub enum OverflowClipBox {
     ContentBox,
 }
 
-#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss)]
+#[derive(
+    Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss, ToShmem,
+)]
 /// Provides a rendering hint to the user agent,
 /// stating what kinds of changes the author expects
 /// to perform on the element
@@ -550,7 +562,7 @@ impl WillChange {
 
 bitflags! {
     /// The change bits that we care about.
-    #[derive(MallocSizeOf, SpecifiedValueInfo, ToComputedValue)]
+    #[derive(MallocSizeOf, SpecifiedValueInfo, ToComputedValue, ToShmem)]
     #[repr(C)]
     pub struct WillChangeBits: u8 {
         /// Whether the stacking context will change.
@@ -646,7 +658,8 @@ impl Parse for WillChange {
 bitflags! {
     /// Values for the `touch-action` property.
     #[cfg_attr(feature = "gecko", derive(MallocSizeOf))]
-    #[derive(SpecifiedValueInfo, ToComputedValue)]
+    #[derive(SpecifiedValueInfo, ToComputedValue, ToShmem)]
+    /// These constants match Gecko's `NS_STYLE_TOUCH_ACTION_*` constants.
     #[value_info(other_values = "auto,none,manipulation,pan-x,pan-y")]
     #[repr(C)]
     pub struct TouchAction: u8 {
@@ -718,7 +731,7 @@ impl Parse for TouchAction {
 }
 
 bitflags! {
-    #[derive(MallocSizeOf, SpecifiedValueInfo, ToComputedValue)]
+    #[derive(MallocSizeOf, SpecifiedValueInfo, ToComputedValue, ToShmem)]
     #[value_info(other_values = "none,strict,content,size,layout,paint")]
     #[repr(C)]
     /// Constants for contain: https://drafts.csswg.org/css-contain/#contain-property
@@ -820,7 +833,7 @@ pub type Perspective = GenericPerspective<NonNegativeLength>;
 
 /// A given transition property, that is either `All`, a longhand or shorthand
 /// property, or an unsupported or custom property.
-#[derive(Clone, Debug, Eq, Hash, MallocSizeOf, PartialEq, ToComputedValue)]
+#[derive(Clone, Debug, Eq, Hash, MallocSizeOf, PartialEq, ToComputedValue, ToShmem)]
 pub enum TransitionProperty {
     /// A shorthand.
     Shorthand(ShorthandId),
@@ -915,7 +928,17 @@ impl TransitionProperty {
 #[allow(missing_docs)]
 #[cfg_attr(feature = "servo", derive(Deserialize, Serialize))]
 #[derive(
-    Clone, Copy, Debug, Eq, Hash, MallocSizeOf, Parse, PartialEq, SpecifiedValueInfo, ToCss,
+    Clone,
+    Copy,
+    Debug,
+    Eq,
+    Hash,
+    MallocSizeOf,
+    Parse,
+    PartialEq,
+    SpecifiedValueInfo,
+    ToCss,
+    ToShmem,
 )]
 /// https://drafts.csswg.org/css-box/#propdef-float
 pub enum Float {
@@ -930,7 +953,17 @@ pub enum Float {
 #[allow(missing_docs)]
 #[cfg_attr(feature = "servo", derive(Deserialize, Serialize))]
 #[derive(
-    Clone, Copy, Debug, Eq, Hash, MallocSizeOf, Parse, PartialEq, SpecifiedValueInfo, ToCss,
+    Clone,
+    Copy,
+    Debug,
+    Eq,
+    Hash,
+    MallocSizeOf,
+    Parse,
+    PartialEq,
+    SpecifiedValueInfo,
+    ToCss,
+    ToShmem,
 )]
 /// https://drafts.csswg.org/css-box/#propdef-clear
 pub enum Clear {
@@ -947,7 +980,17 @@ pub enum Clear {
 #[allow(missing_docs)]
 #[cfg_attr(feature = "servo", derive(Deserialize, Serialize))]
 #[derive(
-    Clone, Copy, Debug, Eq, Hash, MallocSizeOf, Parse, PartialEq, SpecifiedValueInfo, ToCss,
+    Clone,
+    Copy,
+    Debug,
+    Eq,
+    Hash,
+    MallocSizeOf,
+    Parse,
+    PartialEq,
+    SpecifiedValueInfo,
+    ToCss,
+    ToShmem,
 )]
 pub enum Resize {
     None,
@@ -975,6 +1018,7 @@ pub enum Resize {
     SpecifiedValueInfo,
     ToCss,
     ToComputedValue,
+    ToShmem,
 )]
 #[repr(u8)]
 pub enum Appearance {
@@ -1326,6 +1370,7 @@ pub enum Appearance {
     SpecifiedValueInfo,
     ToCss,
     ToComputedValue,
+    ToShmem,
 )]
 #[repr(u8)]
 pub enum BreakBetween {
@@ -1397,6 +1442,7 @@ impl BreakBetween {
     SpecifiedValueInfo,
     ToCss,
     ToComputedValue,
+    ToShmem,
 )]
 #[repr(u8)]
 pub enum BreakWithin {
@@ -1418,6 +1464,7 @@ pub enum BreakWithin {
     SpecifiedValueInfo,
     ToCss,
     ToComputedValue,
+    ToShmem,
 )]
 #[repr(u8)]
 pub enum Overflow {
diff --git a/components/style/values/specified/calc.rs b/components/style/values/specified/calc.rs
index 48389ce5782..b101cd69de7 100644
--- a/components/style/values/specified/calc.rs
+++ b/components/style/values/specified/calc.rs
@@ -65,7 +65,7 @@ pub enum CalcUnit {
 /// relative lengths, and to_computed_pixel_length_without_context() handles
 /// this case. Therefore, if you want to add a new field, please make sure this
 /// function work properly.
-#[derive(Clone, Copy, Debug, Default, MallocSizeOf, PartialEq)]
+#[derive(Clone, Copy, Debug, Default, MallocSizeOf, PartialEq, ToShmem)]
 #[allow(missing_docs)]
 pub struct CalcLengthPercentage {
     pub clamping_mode: AllowedNumericType,
diff --git a/components/style/values/specified/color.rs b/components/style/values/specified/color.rs
index 9ef9ab57f0a..526ed260dbd 100644
--- a/components/style/values/specified/color.rs
+++ b/components/style/values/specified/color.rs
@@ -22,7 +22,7 @@ use style_traits::{CssType, CssWriter, KeywordsCollectFn, ParseError, StyleParse
 use style_traits::{SpecifiedValueInfo, ToCss, ValueParseErrorKind};
 
 /// Specified color value
-#[derive(Clone, Debug, MallocSizeOf, PartialEq)]
+#[derive(Clone, Debug, MallocSizeOf, PartialEq, ToShmem)]
 pub enum Color {
     /// The 'currentColor' keyword
     CurrentColor,
@@ -49,7 +49,7 @@ pub enum Color {
 
 #[cfg(feature = "gecko")]
 mod gecko {
-    #[derive(Clone, Copy, Debug, Eq, Hash, MallocSizeOf, Parse, PartialEq, ToCss)]
+    #[derive(Clone, Copy, Debug, Eq, Hash, MallocSizeOf, Parse, PartialEq, ToCss, ToShmem)]
     pub enum SpecialColorKeyword {
         MozDefaultColor,
         MozDefaultBackgroundColor,
@@ -395,7 +395,7 @@ impl ToComputedValue for Color {
 
 /// Specified color value, but resolved to just RGBA for computed value
 /// with value from color property at the same context.
-#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToCss)]
+#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToCss, ToShmem)]
 pub struct RGBAColor(pub Color);
 
 impl Parse for RGBAColor {
@@ -443,7 +443,7 @@ impl SpecifiedValueInfo for Color {
 /// Specified value for the "color" property, which resolves the `currentcolor`
 /// keyword to the parent color instead of self's color.
 #[cfg_attr(feature = "gecko", derive(MallocSizeOf))]
-#[derive(Clone, Debug, PartialEq, SpecifiedValueInfo, ToCss)]
+#[derive(Clone, Debug, PartialEq, SpecifiedValueInfo, ToCss, ToShmem)]
 pub struct ColorPropertyValue(pub Color);
 
 impl ToComputedValue for ColorPropertyValue {
diff --git a/components/style/values/specified/effects.rs b/components/style/values/specified/effects.rs
index 38a53749605..d8c378a8a7b 100644
--- a/components/style/values/specified/effects.rs
+++ b/components/style/values/specified/effects.rs
@@ -37,7 +37,7 @@ pub type Filter = GenericFilter<Angle, Factor, NonNegativeLength, SimpleShadow,
 pub type Filter = GenericFilter<Angle, Factor, NonNegativeLength, Impossible, Impossible>;
 
 /// A value for the `<factor>` parts in `Filter`.
-#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToCss)]
+#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToCss, ToShmem)]
 pub struct Factor(NumberOrPercentage);
 
 impl Factor {
diff --git a/components/style/values/specified/font.rs b/components/style/values/specified/font.rs
index baae46aed2f..fb4fa805212 100644
--- a/components/style/values/specified/font.rs
+++ b/components/style/values/specified/font.rs
@@ -81,7 +81,7 @@ pub const MAX_FONT_WEIGHT: f32 = 1000.;
 /// A specified font-weight value.
 ///
 /// https://drafts.csswg.org/css-fonts-4/#propdef-font-weight
-#[derive(Clone, Copy, Debug, MallocSizeOf, Parse, PartialEq, SpecifiedValueInfo, ToCss)]
+#[derive(Clone, Copy, Debug, MallocSizeOf, Parse, PartialEq, SpecifiedValueInfo, ToCss, ToShmem)]
 pub enum FontWeight {
     /// `<font-weight-absolute>`
     Absolute(AbsoluteFontWeight),
@@ -143,7 +143,7 @@ impl ToComputedValue for FontWeight {
 /// An absolute font-weight value for a @font-face rule.
 ///
 /// https://drafts.csswg.org/css-fonts-4/#font-weight-absolute-values
-#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToCss)]
+#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToCss, ToShmem)]
 pub enum AbsoluteFontWeight {
     /// A `<number>`, with the additional constraints specified in:
     ///
@@ -319,7 +319,7 @@ impl SpecifiedFontStyle {
 }
 
 /// The specified value of the `font-style` property.
-#[derive(Clone, Copy, Debug, MallocSizeOf, Parse, PartialEq, SpecifiedValueInfo, ToCss)]
+#[derive(Clone, Copy, Debug, MallocSizeOf, Parse, PartialEq, SpecifiedValueInfo, ToCss, ToShmem)]
 #[allow(missing_docs)]
 pub enum FontStyle {
     Specified(SpecifiedFontStyle),
@@ -358,7 +358,7 @@ impl ToComputedValue for FontStyle {
 ///
 /// TODO(emilio): We could derive Parse if we had NonNegativePercentage.
 #[allow(missing_docs)]
-#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToCss)]
+#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToCss, ToShmem)]
 #[repr(u8)]
 pub enum FontStretch {
     Stretch(Percentage),
@@ -368,7 +368,9 @@ pub enum FontStretch {
 }
 
 /// A keyword value for `font-stretch`.
-#[derive(Clone, Copy, Debug, MallocSizeOf, Parse, PartialEq, SpecifiedValueInfo, ToCss)]
+#[derive(
+    Clone, Copy, Debug, MallocSizeOf, Parse, PartialEq, SpecifiedValueInfo, ToCss, ToShmem,
+)]
 #[allow(missing_docs)]
 pub enum FontStretchKeyword {
     Normal,
@@ -481,7 +483,7 @@ impl ToComputedValue for FontStretch {
     }
 }
 
-#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToCss)]
+#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToCss, ToShmem)]
 /// A specified font-size value
 pub enum FontSize {
     /// A length; e.g. 10px.
@@ -513,7 +515,7 @@ impl From<LengthPercentage> for FontSize {
 }
 
 /// Specifies a prioritized list of font family names or generic family names.
-#[derive(Clone, Debug, Eq, Hash, PartialEq, ToCss)]
+#[derive(Clone, Debug, Eq, Hash, PartialEq, ToCss, ToShmem)]
 pub enum FontFamily {
     /// List of `font-family`
     #[css(comma)]
@@ -612,7 +614,7 @@ impl Parse for FamilyName {
     }
 }
 
-#[derive(Clone, Copy, Debug, MallocSizeOf, Parse, PartialEq, SpecifiedValueInfo, ToCss)]
+#[derive(Clone, Copy, Debug, MallocSizeOf, Parse, PartialEq, SpecifiedValueInfo, ToCss, ToShmem)]
 /// Preserve the readability of text when font fallback occurs
 pub enum FontSizeAdjust {
     /// None variant
@@ -1002,7 +1004,7 @@ bitflags! {
     }
 }
 
-#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToCss)]
+#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToCss, ToShmem)]
 /// Set of variant alternates
 pub enum VariantAlternates {
     /// Enables display of stylistic alternates
@@ -1027,7 +1029,7 @@ pub enum VariantAlternates {
     HistoricalForms,
 }
 
-#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToCss)]
+#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToCss, ToShmem)]
 /// List of Variant Alternates
 pub struct VariantAlternatesList(
     #[css(if_empty = "normal", iterable)] pub Box<[VariantAlternates]>,
@@ -1048,7 +1050,7 @@ impl VariantAlternatesList {
     }
 }
 
-#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToCss)]
+#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToCss, ToShmem)]
 /// Control over the selection of these alternate glyphs
 pub enum FontVariantAlternates {
     /// Use alternative glyph from value
@@ -1195,7 +1197,7 @@ macro_rules! impl_variant_east_asian {
         )+
     } => {
         bitflags! {
-            #[derive(MallocSizeOf)]
+            #[derive(MallocSizeOf, ToShmem)]
             /// Vairants for east asian variant
             pub struct VariantEastAsian: u16 {
                 /// None of the features
@@ -1284,7 +1286,7 @@ impl VariantEastAsian {
 impl_gecko_keyword_conversions!(VariantEastAsian, u16);
 
 #[cfg_attr(feature = "gecko", derive(MallocSizeOf))]
-#[derive(Clone, Copy, Debug, PartialEq, SpecifiedValueInfo, ToCss)]
+#[derive(Clone, Copy, Debug, PartialEq, SpecifiedValueInfo, ToCss, ToShmem)]
 /// Allows control of glyph substitution and sizing in East Asian text.
 pub enum FontVariantEastAsian {
     /// Value variant with `variant-east-asian`
@@ -1402,7 +1404,7 @@ macro_rules! impl_variant_ligatures {
         )+
     } => {
         bitflags! {
-            #[derive(MallocSizeOf)]
+            #[derive(MallocSizeOf, ToShmem)]
             /// Variants of ligatures
             pub struct VariantLigatures: u16 {
                 /// Specifies that common default features are enabled
@@ -1495,7 +1497,7 @@ impl VariantLigatures {
 impl_gecko_keyword_conversions!(VariantLigatures, u16);
 
 #[cfg_attr(feature = "gecko", derive(MallocSizeOf))]
-#[derive(Clone, Copy, Debug, PartialEq, SpecifiedValueInfo, ToCss)]
+#[derive(Clone, Copy, Debug, PartialEq, SpecifiedValueInfo, ToCss, ToShmem)]
 /// Ligatures and contextual forms are ways of combining glyphs
 /// to produce more harmonized forms
 pub enum FontVariantLigatures {
@@ -1624,7 +1626,7 @@ macro_rules! impl_variant_numeric {
         )+
     } => {
         bitflags! {
-            #[derive(MallocSizeOf)]
+            #[derive(MallocSizeOf, ToShmem)]
             /// Vairants of numeric values
             pub struct VariantNumeric: u8 {
                 /// None of other variants are enabled.
@@ -1711,7 +1713,7 @@ impl VariantNumeric {
 impl_gecko_keyword_conversions!(VariantNumeric, u8);
 
 #[cfg_attr(feature = "gecko", derive(MallocSizeOf))]
-#[derive(Clone, Copy, Debug, PartialEq, SpecifiedValueInfo, ToCss)]
+#[derive(Clone, Copy, Debug, PartialEq, SpecifiedValueInfo, ToCss, ToShmem)]
 /// Specifies control over numerical forms.
 pub enum FontVariantNumeric {
     /// Value variant with `variant-numeric`
@@ -1820,7 +1822,7 @@ pub type SpecifiedFontFeatureSettings = FontSettings<FeatureTagValue<Integer>>;
 
 /// Define initial settings that apply when the font defined by an @font-face
 /// rule is rendered.
-#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToCss)]
+#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToCss, ToShmem)]
 pub enum FontFeatureSettings {
     /// Value of `FontSettings`
     Value(SpecifiedFontFeatureSettings),
@@ -1864,7 +1866,9 @@ impl Parse for FontFeatureSettings {
     }
 }
 
-#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue)]
+#[derive(
+    Clone, Copy, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToShmem,
+)]
 /// Whether user agents are allowed to synthesize bold or oblique font faces
 /// when a font family lacks bold or italic faces
 pub struct FontSynthesis {
@@ -1964,7 +1968,7 @@ impl From<FontSynthesis> for u8 {
     }
 }
 
-#[derive(Clone, Debug, Eq, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToCss)]
+#[derive(Clone, Debug, Eq, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToCss, ToShmem)]
 /// Allows authors to explicitly specify the language system of the font,
 /// overriding the language system implied by the content language
 pub enum FontLanguageOverride {
@@ -2068,7 +2072,7 @@ pub type SpecifiedFontVariationSettings = FontSettings<VariationValue<Number>>;
 
 /// Define initial settings that apply when the font defined by an @font-face
 /// rule is rendered.
-#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToCss)]
+#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToCss, ToShmem)]
 pub enum FontVariationSettings {
     /// Value of `FontSettings`
     Value(SpecifiedFontVariationSettings),
@@ -2155,7 +2159,15 @@ impl Parse for VariationValue<Number> {
 }
 
 #[derive(
-    Clone, Copy, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss,
+    Clone,
+    Copy,
+    Debug,
+    MallocSizeOf,
+    PartialEq,
+    SpecifiedValueInfo,
+    ToComputedValue,
+    ToCss,
+    ToShmem,
 )]
 /// text-zoom. Enable if true, disable if false
 pub struct XTextZoom(#[css(skip)] pub bool);
@@ -2173,7 +2185,9 @@ impl Parse for XTextZoom {
     }
 }
 
-#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss)]
+#[derive(
+    Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss, ToShmem,
+)]
 /// Internal property that reflects the lang attribute
 pub struct XLang(#[css(skip)] pub Atom);
 
@@ -2199,7 +2213,7 @@ impl Parse for XLang {
 }
 
 #[cfg_attr(feature = "gecko", derive(MallocSizeOf))]
-#[derive(Clone, Copy, Debug, PartialEq, SpecifiedValueInfo, ToCss)]
+#[derive(Clone, Copy, Debug, PartialEq, SpecifiedValueInfo, ToCss, ToShmem)]
 /// Specifies the minimum font size allowed due to changes in scriptlevel.
 /// Ref: https://wiki.mozilla.org/MathML:mstyle
 pub struct MozScriptMinSize(pub NoCalcLength);
@@ -2226,7 +2240,7 @@ impl Parse for MozScriptMinSize {
 }
 
 #[cfg_attr(feature = "gecko", derive(MallocSizeOf))]
-#[derive(Clone, Copy, Debug, PartialEq, SpecifiedValueInfo, ToCss)]
+#[derive(Clone, Copy, Debug, PartialEq, SpecifiedValueInfo, ToCss, ToShmem)]
 /// Changes the scriptlevel in effect for the children.
 /// Ref: https://wiki.mozilla.org/MathML:mstyle
 ///
@@ -2261,7 +2275,7 @@ impl Parse for MozScriptLevel {
 }
 
 #[cfg_attr(feature = "gecko", derive(MallocSizeOf))]
-#[derive(Clone, Copy, Debug, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss)]
+#[derive(Clone, Copy, Debug, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss, ToShmem)]
 /// Specifies the multiplier to be used to adjust font size
 /// due to changes in scriptlevel.
 ///
diff --git a/components/style/values/specified/image.rs b/components/style/values/specified/image.rs
index c9d0f10215d..572db0ca1eb 100644
--- a/components/style/values/specified/image.rs
+++ b/components/style/values/specified/image.rs
@@ -96,7 +96,7 @@ pub type GradientKind =
     generic::GradientKind<LineDirection, Length, LengthPercentage, GradientPosition, Angle>;
 
 /// A specified gradient line direction.
-#[derive(Clone, Debug, MallocSizeOf, PartialEq)]
+#[derive(Clone, Debug, MallocSizeOf, PartialEq, ToShmem)]
 pub enum LineDirection {
     /// An angular direction.
     Angle(Angle),
@@ -115,7 +115,7 @@ pub enum LineDirection {
 }
 
 /// A binary enum to hold either Position or LegacyPosition.
-#[derive(Clone, Debug, MallocSizeOf, PartialEq, ToCss)]
+#[derive(Clone, Debug, MallocSizeOf, PartialEq, ToCss, ToShmem)]
 #[cfg(feature = "gecko")]
 pub enum GradientPosition {
     /// 1, 2, 3, 4-valued <position>.
diff --git a/components/style/values/specified/length.rs b/components/style/values/specified/length.rs
index 631de5c87ec..fcbae0aa2d6 100644
--- a/components/style/values/specified/length.rs
+++ b/components/style/values/specified/length.rs
@@ -56,7 +56,7 @@ pub fn au_to_int_px(au: f32) -> i32 {
 }
 
 /// A font relative length.
-#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, ToCss)]
+#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, ToCss, ToShmem)]
 pub enum FontRelativeLength {
     /// A "em" value: https://drafts.csswg.org/css-values/#em
     #[css(dimension)]
@@ -236,7 +236,7 @@ impl FontRelativeLength {
 /// A viewport-relative length.
 ///
 /// <https://drafts.csswg.org/css-values/#viewport-relative-lengths>
-#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, ToCss)]
+#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, ToCss, ToShmem)]
 pub enum ViewportPercentageLength {
     /// A vw unit: https://drafts.csswg.org/css-values/#vw
     #[css(dimension)]
@@ -285,7 +285,7 @@ impl ViewportPercentageLength {
 }
 
 /// HTML5 "character width", as defined in HTML5 § 14.5.4.
-#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, ToCss)]
+#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, ToCss, ToShmem)]
 pub struct CharacterWidth(pub i32);
 
 impl CharacterWidth {
@@ -303,7 +303,7 @@ impl CharacterWidth {
 }
 
 /// Represents an absolute length with its unit
-#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, ToCss)]
+#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, ToCss, ToShmem)]
 pub enum AbsoluteLength {
     /// An absolute length in pixels (px)
     #[css(dimension)]
@@ -409,7 +409,7 @@ impl Add<AbsoluteLength> for AbsoluteLength {
 /// A `<length>` without taking `calc` expressions into account
 ///
 /// <https://drafts.csswg.org/css-values/#lengths>
-#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, ToCss)]
+#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, ToCss, ToShmem)]
 pub enum NoCalcLength {
     /// An absolute length
     ///
@@ -522,7 +522,7 @@ impl Zero for NoCalcLength {
 /// This is commonly used for the `<length>` values.
 ///
 /// <https://drafts.csswg.org/css-values/#lengths>
-#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToCss)]
+#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToCss, ToShmem)]
 pub enum Length {
     /// The internal length type that cannot parse `calc`
     NoCalc(NoCalcLength),
@@ -742,7 +742,7 @@ impl NonNegativeLength {
 ///
 /// https://drafts.csswg.org/css-values-4/#typedef-length-percentage
 #[allow(missing_docs)]
-#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToCss)]
+#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToCss, ToShmem)]
 pub enum LengthPercentage {
     Length(NoCalcLength),
     Percentage(computed::Percentage),
diff --git a/components/style/values/specified/list.rs b/components/style/values/specified/list.rs
index dffce9a3001..bf1a17799b2 100644
--- a/components/style/values/specified/list.rs
+++ b/components/style/values/specified/list.rs
@@ -15,7 +15,9 @@ use style_traits::{ParseError, StyleParseErrorKind};
 
 /// Specified and computed `list-style-type` property.
 #[cfg(feature = "gecko")]
-#[derive(Clone, Debug, Eq, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss)]
+#[derive(
+    Clone, Debug, Eq, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss, ToShmem,
+)]
 pub enum ListStyleType {
     /// <counter-style> | none
     CounterStyle(CounterStyleOrNone),
@@ -74,7 +76,9 @@ impl Parse for ListStyleType {
 }
 
 /// A quote pair.
-#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss)]
+#[derive(
+    Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss, ToShmem,
+)]
 pub struct QuotePair {
     /// The opening quote.
     pub opening: Box<str>,
@@ -84,7 +88,9 @@ pub struct QuotePair {
 }
 
 /// Specified and computed `quotes` property.
-#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss)]
+#[derive(
+    Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss, ToShmem,
+)]
 pub struct Quotes(
     #[css(iterable, if_empty = "none")]
     #[ignore_malloc_size_of = "Arc"]
@@ -137,6 +143,7 @@ impl Parse for Quotes {
     SpecifiedValueInfo,
     ToComputedValue,
     ToCss,
+    ToShmem,
 )]
 #[repr(u8)]
 pub enum MozListReversed {
diff --git a/components/style/values/specified/mod.rs b/components/style/values/specified/mod.rs
index 919cb0cb341..30f80fd44c2 100644
--- a/components/style/values/specified/mod.rs
+++ b/components/style/values/specified/mod.rs
@@ -159,7 +159,7 @@ fn parse_number_with_clamping_mode<'i, 't>(
 /// A CSS `<number>` specified value.
 ///
 /// https://drafts.csswg.org/css-values-3/#number-value
-#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, PartialOrd)]
+#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, PartialOrd, ToShmem)]
 pub struct Number {
     /// The numeric value itself.
     value: CSSFloat,
@@ -346,7 +346,7 @@ impl Parse for GreaterThanOrEqualToOneNumber {
 ///
 /// FIXME(emilio): Should probably use Either.
 #[allow(missing_docs)]
-#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToCss)]
+#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToCss, ToShmem)]
 pub enum NumberOrPercentage {
     Percentage(Percentage),
     Number(Number),
@@ -406,7 +406,9 @@ impl Parse for NonNegativeNumberOrPercentage {
 }
 
 #[allow(missing_docs)]
-#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, PartialOrd, SpecifiedValueInfo, ToCss)]
+#[derive(
+    Clone, Copy, Debug, MallocSizeOf, PartialEq, PartialOrd, SpecifiedValueInfo, ToCss, ToShmem,
+)]
 pub struct Opacity(Number);
 
 impl Parse for Opacity {
@@ -442,7 +444,7 @@ impl ToComputedValue for Opacity {
 /// A specified `<integer>`, optionally coming from a `calc()` expression.
 ///
 /// <https://drafts.csswg.org/css-values/#integers>
-#[derive(Clone, Copy, Debug, Eq, MallocSizeOf, PartialEq, PartialOrd)]
+#[derive(Clone, Copy, Debug, Eq, MallocSizeOf, PartialEq, PartialOrd, ToShmem)]
 pub struct Integer {
     value: CSSInteger,
     was_calc: bool,
@@ -706,7 +708,9 @@ impl AllowQuirks {
 /// An attr(...) rule
 ///
 /// `[namespace? `|`]? ident`
-#[derive(Clone, Debug, Eq, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue)]
+#[derive(
+    Clone, Debug, Eq, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToShmem,
+)]
 #[css(function)]
 pub struct Attr {
     /// Optional namespace prefix and URL.
diff --git a/components/style/values/specified/motion.rs b/components/style/values/specified/motion.rs
index aec168ac740..d9d104bf9c8 100644
--- a/components/style/values/specified/motion.rs
+++ b/components/style/values/specified/motion.rs
@@ -23,6 +23,7 @@ use style_traits::{ParseError, StyleParseErrorKind};
     ToAnimatedZero,
     ToComputedValue,
     ToCss,
+    ToShmem,
 )]
 pub enum OffsetPath {
     // We could merge SVGPathData into ShapeSource, so we could reuse them. However,
diff --git a/components/style/values/specified/outline.rs b/components/style/values/specified/outline.rs
index 398315cbf93..709c3a94773 100644
--- a/components/style/values/specified/outline.rs
+++ b/components/style/values/specified/outline.rs
@@ -22,6 +22,7 @@ use style_traits::ParseError;
     SpecifiedValueInfo,
     ToComputedValue,
     ToCss,
+    ToShmem,
 )]
 #[repr(C, u8)]
 /// <https://drafts.csswg.org/css-ui/#propdef-outline-style>
diff --git a/components/style/values/specified/percentage.rs b/components/style/values/specified/percentage.rs
index 10fecc3a216..acfa6db64af 100644
--- a/components/style/values/specified/percentage.rs
+++ b/components/style/values/specified/percentage.rs
@@ -15,7 +15,7 @@ use style_traits::values::specified::AllowedNumericType;
 use style_traits::{CssWriter, ParseError, SpecifiedValueInfo, ToCss};
 
 /// A percentage value.
-#[derive(Clone, Copy, Debug, Default, MallocSizeOf, PartialEq)]
+#[derive(Clone, Copy, Debug, Default, MallocSizeOf, PartialEq, ToShmem)]
 pub struct Percentage {
     /// The percentage value as a float.
     ///
diff --git a/components/style/values/specified/position.rs b/components/style/values/specified/position.rs
index f60767f1656..43f5b2e4ae2 100644
--- a/components/style/values/specified/position.rs
+++ b/components/style/values/specified/position.rs
@@ -35,7 +35,7 @@ pub type HorizontalPosition = PositionComponent<X>;
 pub type VerticalPosition = PositionComponent<Y>;
 
 /// The specified value of a component of a CSS `<position>`.
-#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToCss)]
+#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToCss, ToShmem)]
 pub enum PositionComponent<S> {
     /// `center`
     Center,
@@ -58,6 +58,7 @@ pub enum PositionComponent<S> {
     SpecifiedValueInfo,
     ToComputedValue,
     ToCss,
+    ToShmem,
 )]
 #[allow(missing_docs)]
 pub enum X {
@@ -78,6 +79,7 @@ pub enum X {
     SpecifiedValueInfo,
     ToComputedValue,
     ToCss,
+    ToShmem,
 )]
 #[allow(missing_docs)]
 pub enum Y {
@@ -434,7 +436,16 @@ impl ToCss for LegacyPosition {
 }
 
 #[derive(
-    Clone, Copy, Debug, Eq, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss,
+    Clone,
+    Copy,
+    Debug,
+    Eq,
+    MallocSizeOf,
+    PartialEq,
+    SpecifiedValueInfo,
+    ToComputedValue,
+    ToCss,
+    ToShmem,
 )]
 /// Auto-placement algorithm Option
 pub enum AutoFlow {
@@ -447,7 +458,16 @@ pub enum AutoFlow {
 }
 
 #[derive(
-    Clone, Copy, Debug, Eq, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss,
+    Clone,
+    Copy,
+    Debug,
+    Eq,
+    MallocSizeOf,
+    PartialEq,
+    SpecifiedValueInfo,
+    ToComputedValue,
+    ToCss,
+    ToShmem,
 )]
 /// Controls how the auto-placement algorithm works
 /// specifying exactly how auto-placed items get flowed into the grid
@@ -548,7 +568,7 @@ impl From<GridAutoFlow> for u8 {
 }
 
 #[cfg_attr(feature = "gecko", derive(MallocSizeOf))]
-#[derive(Clone, Debug, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss)]
+#[derive(Clone, Debug, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss, ToShmem)]
 /// https://drafts.csswg.org/css-grid/#named-grid-area
 pub struct TemplateAreas {
     /// `named area` containing for each template area
@@ -654,7 +674,9 @@ impl Parse for TemplateAreas {
 }
 
 /// Arc type for `Arc<TemplateAreas>`
-#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss)]
+#[derive(
+    Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss, ToShmem,
+)]
 pub struct TemplateAreasArc(#[ignore_malloc_size_of = "Arc"] pub Arc<TemplateAreas>);
 
 impl Parse for TemplateAreasArc {
@@ -669,7 +691,7 @@ impl Parse for TemplateAreasArc {
 }
 
 #[cfg_attr(feature = "gecko", derive(MallocSizeOf))]
-#[derive(Clone, Debug, PartialEq, SpecifiedValueInfo)]
+#[derive(Clone, Debug, PartialEq, SpecifiedValueInfo, ToShmem)]
 /// Not associated with any particular grid item, but can
 /// be referenced from the grid-placement properties.
 pub struct NamedArea {
diff --git a/components/style/values/specified/resolution.rs b/components/style/values/specified/resolution.rs
index d0d12dd7bba..f8854226b53 100644
--- a/components/style/values/specified/resolution.rs
+++ b/components/style/values/specified/resolution.rs
@@ -12,7 +12,7 @@ use cssparser::{Parser, Token};
 use style_traits::{ParseError, StyleParseErrorKind};
 
 /// A specified resolution.
-#[derive(Clone, Debug, MallocSizeOf, PartialEq, ToCss)]
+#[derive(Clone, Debug, MallocSizeOf, PartialEq, ToCss, ToShmem)]
 pub enum Resolution {
     /// Dots per inch.
     #[css(dimension)]
diff --git a/components/style/values/specified/svg.rs b/components/style/values/specified/svg.rs
index 556e995c02f..c5fe3fe2543 100644
--- a/components/style/values/specified/svg.rs
+++ b/components/style/values/specified/svg.rs
@@ -128,7 +128,9 @@ const PAINT_ORDER_MASK: u8 = 0b11;
 ///
 /// Higher priority values, i.e. the values specified first,
 /// will be painted first (and may be covered by paintings of lower priority)
-#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue)]
+#[derive(
+    Clone, Copy, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToShmem,
+)]
 pub struct SVGPaintOrder(pub u8);
 
 impl SVGPaintOrder {
@@ -235,7 +237,9 @@ impl ToCss for SVGPaintOrder {
 
 /// Specified MozContextProperties value.
 /// Nonstandard (https://developer.mozilla.org/en-US/docs/Web/CSS/-moz-context-properties)
-#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss)]
+#[derive(
+    Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss, ToShmem,
+)]
 pub struct MozContextProperties(pub CustomIdent);
 
 impl Parse for MozContextProperties {
diff --git a/components/style/values/specified/svg_path.rs b/components/style/values/specified/svg_path.rs
index 86059c9ab2a..38c743ab756 100644
--- a/components/style/values/specified/svg_path.rs
+++ b/components/style/values/specified/svg_path.rs
@@ -19,7 +19,14 @@ use style_traits::{CssWriter, ParseError, StyleParseErrorKind, ToCss};
 ///
 /// https://www.w3.org/TR/SVG11/paths.html#PathData
 #[derive(
-    Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToAnimatedZero, ToComputedValue,
+    Clone,
+    Debug,
+    MallocSizeOf,
+    PartialEq,
+    SpecifiedValueInfo,
+    ToAnimatedZero,
+    ToComputedValue,
+    ToShmem,
 )]
 pub struct SVGPathData(Box<[PathCommand]>);
 
@@ -147,6 +154,7 @@ impl ComputeSquaredDistance for SVGPathData {
     PartialEq,
     SpecifiedValueInfo,
     ToAnimatedZero,
+    ToShmem,
 )]
 #[allow(missing_docs)]
 #[repr(C, u8)]
@@ -473,6 +481,7 @@ impl ToCss for PathCommand {
     PartialEq,
     SpecifiedValueInfo,
     ToAnimatedZero,
+    ToShmem,
 )]
 #[repr(u8)]
 pub enum IsAbsolute {
@@ -501,6 +510,7 @@ impl IsAbsolute {
     SpecifiedValueInfo,
     ToAnimatedZero,
     ToCss,
+    ToShmem,
 )]
 #[repr(C)]
 pub struct CoordPair(CSSFloat, CSSFloat);
@@ -514,7 +524,7 @@ impl CoordPair {
 }
 
 /// The EllipticalArc flag type.
-#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo)]
+#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToShmem)]
 #[repr(C)]
 pub struct ArcFlag(bool);
 
diff --git a/components/style/values/specified/table.rs b/components/style/values/specified/table.rs
index b746f572740..54680c40d5e 100644
--- a/components/style/values/specified/table.rs
+++ b/components/style/values/specified/table.rs
@@ -9,7 +9,15 @@ use cssparser::Parser;
 use style_traits::{ParseError, StyleParseErrorKind};
 
 #[derive(
-    Clone, Copy, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss,
+    Clone,
+    Copy,
+    Debug,
+    MallocSizeOf,
+    PartialEq,
+    SpecifiedValueInfo,
+    ToComputedValue,
+    ToCss,
+    ToShmem,
 )]
 /// span. for `<col span>` pres attr
 pub struct XSpan(#[css(skip)] pub i32);
diff --git a/components/style/values/specified/text.rs b/components/style/values/specified/text.rs
index 1c2f8499af5..75a731d449f 100644
--- a/components/style/values/specified/text.rs
+++ b/components/style/values/specified/text.rs
@@ -134,7 +134,7 @@ impl ToComputedValue for LineHeight {
 }
 
 /// A generic value for the `text-overflow` property.
-#[derive(Clone, Debug, Eq, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToCss)]
+#[derive(Clone, Debug, Eq, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToCss, ToShmem)]
 pub enum TextOverflowSide {
     /// Clip inline content.
     Clip,
@@ -168,7 +168,7 @@ impl Parse for TextOverflowSide {
     }
 }
 
-#[derive(Clone, Debug, Eq, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToCss)]
+#[derive(Clone, Debug, Eq, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToCss, ToShmem)]
 /// text-overflow. Specifies rendering when inline content overflows its line box edge.
 pub struct TextOverflow {
     /// First value. Applies to end line box edge if no second is supplied; line-left edge otherwise.
@@ -228,7 +228,7 @@ impl ToComputedValue for TextOverflow {
 }
 
 bitflags! {
-    #[derive(MallocSizeOf, SpecifiedValueInfo, ToComputedValue)]
+    #[derive(MallocSizeOf, SpecifiedValueInfo, ToComputedValue, ToShmem)]
     #[value_info(other_values = "none,underline,overline,line-through,blink")]
     #[repr(C)]
     /// Specified keyword values for the text-decoration-line property.
@@ -365,6 +365,7 @@ impl TextDecorationLine {
     SpecifiedValueInfo,
     ToComputedValue,
     ToCss,
+    ToShmem,
 )]
 #[allow(missing_docs)]
 pub enum TextAlignKeyword {
@@ -393,7 +394,7 @@ pub enum TextAlignKeyword {
 
 /// Specified value of text-align property.
 #[cfg_attr(feature = "gecko", derive(MallocSizeOf))]
-#[derive(Clone, Copy, Debug, Eq, Hash, Parse, PartialEq, SpecifiedValueInfo, ToCss)]
+#[derive(Clone, Copy, Debug, Eq, Hash, Parse, PartialEq, SpecifiedValueInfo, ToCss, ToShmem)]
 pub enum TextAlign {
     /// Keyword value of text-align property.
     Keyword(TextAlignKeyword),
@@ -470,7 +471,7 @@ impl ToComputedValue for TextAlign {
 }
 
 /// Specified value of text-emphasis-style property.
-#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToCss)]
+#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToCss, ToShmem)]
 pub enum TextEmphasisStyle {
     /// <fill> <shape>
     Keyword(TextEmphasisKeywordValue),
@@ -481,7 +482,7 @@ pub enum TextEmphasisStyle {
 }
 
 /// Keyword value for the text-emphasis-style property
-#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToCss)]
+#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToCss, ToShmem)]
 pub enum TextEmphasisKeywordValue {
     /// <fill>
     Fill(TextEmphasisFillMode),
@@ -510,7 +511,9 @@ impl TextEmphasisKeywordValue {
 }
 
 /// Fill mode for the text-emphasis-style property
-#[derive(Clone, Copy, Debug, MallocSizeOf, Parse, PartialEq, SpecifiedValueInfo, ToCss)]
+#[derive(
+    Clone, Copy, Debug, MallocSizeOf, Parse, PartialEq, SpecifiedValueInfo, ToCss, ToShmem,
+)]
 pub enum TextEmphasisFillMode {
     /// `filled`
     Filled,
@@ -519,7 +522,9 @@ pub enum TextEmphasisFillMode {
 }
 
 /// Shape keyword for the text-emphasis-style property
-#[derive(Clone, Copy, Debug, Eq, MallocSizeOf, Parse, PartialEq, SpecifiedValueInfo, ToCss)]
+#[derive(
+    Clone, Copy, Debug, Eq, MallocSizeOf, Parse, PartialEq, SpecifiedValueInfo, ToCss, ToShmem,
+)]
 pub enum TextEmphasisShapeKeyword {
     /// `dot`
     Dot,
@@ -669,6 +674,7 @@ impl Parse for TextEmphasisStyle {
     SpecifiedValueInfo,
     ToComputedValue,
     ToCss,
+    ToShmem,
 )]
 pub enum TextEmphasisHorizontalWritingModeValue {
     /// Draw marks over the text in horizontal writing mode.
@@ -689,6 +695,7 @@ pub enum TextEmphasisHorizontalWritingModeValue {
     SpecifiedValueInfo,
     ToComputedValue,
     ToCss,
+    ToShmem,
 )]
 pub enum TextEmphasisVerticalWritingModeValue {
     /// Draws marks to the right of the text in vertical writing mode.
@@ -699,7 +706,15 @@ pub enum TextEmphasisVerticalWritingModeValue {
 
 /// Specified value of `text-emphasis-position` property.
 #[derive(
-    Clone, Copy, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss,
+    Clone,
+    Copy,
+    Debug,
+    MallocSizeOf,
+    PartialEq,
+    SpecifiedValueInfo,
+    ToComputedValue,
+    ToCss,
+    ToShmem,
 )]
 pub struct TextEmphasisPosition(
     pub TextEmphasisHorizontalWritingModeValue,
@@ -800,6 +815,7 @@ impl From<TextEmphasisPosition> for u8 {
     SpecifiedValueInfo,
     ToComputedValue,
     ToCss,
+    ToShmem,
 )]
 #[allow(missing_docs)]
 pub enum WordBreak {
@@ -827,6 +843,7 @@ pub enum WordBreak {
     SpecifiedValueInfo,
     ToComputedValue,
     ToCss,
+    ToShmem,
 )]
 #[allow(missing_docs)]
 pub enum OverflowWrap {
diff --git a/components/style/values/specified/time.rs b/components/style/values/specified/time.rs
index 9f2aa6f3580..f46925bc5c1 100644
--- a/components/style/values/specified/time.rs
+++ b/components/style/values/specified/time.rs
@@ -15,7 +15,7 @@ use style_traits::values::specified::AllowedNumericType;
 use style_traits::{CssWriter, ParseError, SpecifiedValueInfo, StyleParseErrorKind, ToCss};
 
 /// A time value according to CSS-VALUES § 6.2.
-#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq)]
+#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, ToShmem)]
 pub struct Time {
     seconds: CSSFloat,
     unit: TimeUnit,
@@ -23,7 +23,7 @@ pub struct Time {
 }
 
 /// A time unit.
-#[derive(Clone, Copy, Debug, Eq, MallocSizeOf, PartialEq)]
+#[derive(Clone, Copy, Debug, Eq, MallocSizeOf, PartialEq, ToShmem)]
 pub enum TimeUnit {
     /// `s`
     Second,
diff --git a/components/style/values/specified/transform.rs b/components/style/values/specified/transform.rs
index 92ca953159f..a4dc87d3217 100644
--- a/components/style/values/specified/transform.rs
+++ b/components/style/values/specified/transform.rs
@@ -232,7 +232,7 @@ impl Parse for Transform {
 }
 
 /// The specified value of a component of a CSS `<transform-origin>`.
-#[derive(Clone, Debug, MallocSizeOf, Parse, PartialEq, SpecifiedValueInfo, ToCss)]
+#[derive(Clone, Debug, MallocSizeOf, Parse, PartialEq, SpecifiedValueInfo, ToCss, ToShmem)]
 pub enum OriginComponent<S> {
     /// `center`
     Center,
diff --git a/components/style/values/specified/ui.rs b/components/style/values/specified/ui.rs
index 0ccca5d359e..cac8e49309a 100644
--- a/components/style/values/specified/ui.rs
+++ b/components/style/values/specified/ui.rs
@@ -56,7 +56,9 @@ impl Parse for CursorImage {
 }
 
 /// Specified value of `-moz-force-broken-image-icon`
-#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue)]
+#[derive(
+    Clone, Copy, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToShmem,
+)]
 pub struct MozForceBrokenImageIcon(pub bool);
 
 impl MozForceBrokenImageIcon {
@@ -139,6 +141,7 @@ impl Parse for ScrollbarColor {
     SpecifiedValueInfo,
     ToComputedValue,
     ToCss,
+    ToShmem,
 )]
 #[repr(u8)]
 pub enum UserSelect {
@@ -166,6 +169,7 @@ pub enum UserSelect {
     SpecifiedValueInfo,
     ToComputedValue,
     ToCss,
+    ToShmem,
 )]
 #[repr(u8)]
 pub enum CursorKind {
diff --git a/components/style_traits/Cargo.toml b/components/style_traits/Cargo.toml
index 53d3baf8845..846579d462c 100644
--- a/components/style_traits/Cargo.toml
+++ b/components/style_traits/Cargo.toml
@@ -26,3 +26,5 @@ webrender_api = {git = "https://github.com/servo/webrender", optional = true}
 servo_atoms = {path = "../atoms", optional = true}
 servo_arc = { path = "../servo_arc" }
 servo_url = { path = "../url", optional = true }
+to_shmem = { path = "../to_shmem" }
+to_shmem_derive = { path = "../to_shmem_derive" }
diff --git a/components/style_traits/lib.rs b/components/style_traits/lib.rs
index 3df0f6a24e5..bce0a507f75 100644
--- a/components/style_traits/lib.rs
+++ b/components/style_traits/lib.rs
@@ -28,6 +28,9 @@ extern crate servo_arc;
 extern crate servo_atoms;
 #[cfg(feature = "servo")]
 extern crate servo_url;
+extern crate to_shmem;
+#[macro_use]
+extern crate to_shmem_derive;
 #[cfg(feature = "servo")]
 extern crate webrender_api;
 #[cfg(feature = "servo")]
diff --git a/components/style_traits/values.rs b/components/style_traits/values.rs
index 46751541319..5c3f3ab255d 100644
--- a/components/style_traits/values.rs
+++ b/components/style_traits/values.rs
@@ -441,7 +441,7 @@ macro_rules! define_css_keyword_enum {
     (pub enum $name:ident { $($variant:ident = $css:expr,)+ }) => {
         #[allow(missing_docs)]
         #[cfg_attr(feature = "servo", derive(Deserialize, Serialize))]
-        #[derive(Clone, Copy, Debug, Eq, Hash, MallocSizeOf, PartialEq)]
+        #[derive(Clone, Copy, Debug, Eq, Hash, MallocSizeOf, PartialEq, ToShmem)]
         pub enum $name {
             $($variant),+
         }
@@ -497,7 +497,7 @@ pub mod specified {
 
     /// Whether to allow negative lengths or not.
     #[repr(u8)]
-    #[derive(Clone, Copy, Debug, Eq, MallocSizeOf, PartialEq, PartialOrd)]
+    #[derive(Clone, Copy, Debug, Eq, MallocSizeOf, PartialEq, PartialOrd, ToShmem)]
     pub enum AllowedNumericType {
         /// Allow all kind of numeric values.
         All,
diff --git a/components/style_traits/viewport.rs b/components/style_traits/viewport.rs
index f1aa18412e3..fb10345c1b2 100644
--- a/components/style_traits/viewport.rs
+++ b/components/style_traits/viewport.rs
@@ -80,7 +80,7 @@ impl ToCss for ViewportConstraints {
 }
 
 /// <https://drafts.csswg.org/css-device-adapt/#descdef-viewport-zoom>
-#[derive(Clone, Copy, Debug, PartialEq)]
+#[derive(Clone, Copy, Debug, PartialEq, ToShmem)]
 #[cfg_attr(feature = "servo", derive(MallocSizeOf))]
 pub enum Zoom {
     /// A number value.

From 7aac260c5d19f716f5069909e818605d59afc56d Mon Sep 17 00:00:00 2001
From: Cameron McCormack <cam@mcc.id.au>
Date: Sat, 30 Mar 2019 00:16:27 +0000
Subject: [PATCH 23/59] style: Add FFI API to use SharedMemoryBuilder.

Differential Revision: https://phabricator.services.mozilla.com/D17198
---
 components/style/gecko/boxed_types.rs | 21 +++++++++++++++++++++
 components/style/gecko/mod.rs         |  1 +
 2 files changed, 22 insertions(+)
 create mode 100644 components/style/gecko/boxed_types.rs

diff --git a/components/style/gecko/boxed_types.rs b/components/style/gecko/boxed_types.rs
new file mode 100644
index 00000000000..857f99e1489
--- /dev/null
+++ b/components/style/gecko/boxed_types.rs
@@ -0,0 +1,21 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+//! FFI implementations for types listed in ServoBoxedTypeList.h.
+
+use crate::gecko_bindings::sugar::ownership::{HasBoxFFI, HasFFI, HasSimpleFFI};
+use to_shmem::SharedMemoryBuilder;
+
+// TODO(heycam): The FFI impls for most of the types in ServoBoxedTypeList.h are spread across
+// various files at the moment, but should probably all move here, and use macros to define
+// them more succinctly, like we do in arc_types.rs.
+
+#[cfg(feature = "gecko")]
+unsafe impl HasFFI for SharedMemoryBuilder {
+    type FFIType = crate::gecko_bindings::bindings::RawServoSharedMemoryBuilder;
+}
+#[cfg(feature = "gecko")]
+unsafe impl HasSimpleFFI for SharedMemoryBuilder {}
+#[cfg(feature = "gecko")]
+unsafe impl HasBoxFFI for SharedMemoryBuilder {}
diff --git a/components/style/gecko/mod.rs b/components/style/gecko/mod.rs
index 1051f84fc52..fb332dcce6e 100644
--- a/components/style/gecko/mod.rs
+++ b/components/style/gecko/mod.rs
@@ -8,6 +8,7 @@
 mod non_ts_pseudo_class_list;
 
 pub mod arc_types;
+pub mod boxed_types;
 pub mod conversions;
 pub mod data;
 pub mod media_features;

From debd837bf062ef1f2e4d28e81e72a979ac5165ae Mon Sep 17 00:00:00 2001
From: Cameron McCormack <cam@mcc.id.au>
Date: Sat, 30 Mar 2019 00:16:29 +0000
Subject: [PATCH 24/59] style: Add FFI API to create a StyleSheet backed by
 shared data.

Differential Revision: https://phabricator.services.mozilla.com/D17199
---
 components/style/stylesheets/stylesheet.rs | 28 ++++++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/components/style/stylesheets/stylesheet.rs b/components/style/stylesheets/stylesheet.rs
index 77fa008612d..5b8c8753248 100644
--- a/components/style/stylesheets/stylesheet.rs
+++ b/components/style/stylesheets/stylesheet.rs
@@ -107,6 +107,34 @@ impl StylesheetContents {
         }
     }
 
+    /// Creates a new StylesheetContents with the specified pre-parsed rules,
+    /// origin, URL data, and quirks mode.
+    ///
+    /// Since the rules have already been parsed, and the intention is that
+    /// this function is used for read only User Agent style sheets, an empty
+    /// namespace map is used, and the source map and source URLs are set to
+    /// None.
+    ///
+    /// An empty namespace map should be fine, as it is only used for parsing,
+    /// not serialization of existing selectors.  Since UA sheets are read only,
+    /// we should never need the namespace map.
+    pub fn from_shared_data(
+        rules: Arc<Locked<CssRules>>,
+        origin: Origin,
+        url_data: UrlExtraData,
+        quirks_mode: QuirksMode,
+    ) -> Self {
+        Self {
+            rules,
+            origin,
+            url_data: RwLock::new(url_data),
+            namespaces: RwLock::new(Namespaces::default()),
+            quirks_mode,
+            source_map_url: RwLock::new(None),
+            source_url: RwLock::new(None),
+        }
+    }
+
     /// Returns a reference to the list of rules.
     #[inline]
     pub fn rules<'a, 'b: 'a>(&'a self, guard: &'b SharedRwLockReadGuard) -> &'a [CssRule] {

From 2f8e05e9e0fc4a4311451e77ef150bdd8f16b151 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Emilio=20Cobos=20=C3=81lvarez?= <emilio@crisal.io>
Date: Sat, 30 Mar 2019 20:18:33 +0000
Subject: [PATCH 25/59] style: Autogenerate Servo_ binding functions with
 cbindgen.

This depends on https://github.com/eqrion/cbindgen/pull/308. Other than that,
this should be ready to go.

There's still a bit more magic than what I'd like to eventually. I should be
able to make cbindgen not rename types if it doesn't know about them, or
something.

But this removes most of the manual binding function implementations (all but
the ones that are declared via macros, which cbindgen doesn't see across).

I need to give up on the _Drop functions taking an Owned<T> because of
instantiation order fiasco. In order to define DefaultDelete I need Owned to be
complete, but I cannot do it after including the generated file since some
declarations already instantiate the specialization. Oh well.

Differential Revision: https://phabricator.services.mozilla.com/D24798
---
 components/style/cbindgen.toml                | 239 ------------------
 .../style/gecko_bindings/sugar/ownership.rs   |  16 +-
 2 files changed, 8 insertions(+), 247 deletions(-)
 delete mode 100644 components/style/cbindgen.toml

diff --git a/components/style/cbindgen.toml b/components/style/cbindgen.toml
deleted file mode 100644
index cd910f0be9b..00000000000
--- a/components/style/cbindgen.toml
+++ /dev/null
@@ -1,239 +0,0 @@
-header = """/* This Source Code Form is subject to the terms of the Mozilla Public
- * License, v. 2.0. If a copy of the MPL was not distributed with this
- * file, You can obtain one at https://mozilla.org/MPL/2.0/. */"""
-autogen_warning = """/* DO NOT MODIFY THIS MANUALLY! This file was generated using cbindgen.
- * To generate this file:
- *   1. Get the latest cbindgen using `cargo install --force cbindgen`
- *      a. Alternatively, you can clone `https://github.com/eqrion/cbindgen` and use a tagged release
- *   2. Run `rustup run nightly cbindgen toolkit/library/rust/ --lockfile Cargo.lock --crate style -o layout/style/ServoStyleConsts.h`
- */
-#include "nsCoord.h"
-#include "Units.h"
-#include "mozilla/gfx/Types.h"
-class nsAtom;
-namespace mozilla {
-  class WritingMode;
-  enum HalfCorner : uint8_t;
-  enum LogicalSide : uint8_t;
-  namespace css {
-    struct URLValue;
-  }
-
-  // Work-around weird cbindgen renaming.
-  typedef css::URLValue StyleURLValue;
-  typedef nsAtom StylensAtom;
-}
-"""
-include_guard = "mozilla_ServoStyleConsts_h"
-include_version = true
-braces = "SameLine"
-line_length = 80
-tab_width = 2
-language = "C++"
-namespaces = ["mozilla"]
-
-[parse]
-parse_deps = true
-include = ["cssparser", "style_traits"]
-
-[struct]
-derive_eq = true
-derive_neq = true
-
-[macro_expansion]
-bitflags = true
-
-[enum]
-derive_helper_methods = true
-derive_const_casts = true
-cast_assert_name = "MOZ_ASSERT"
-
-[export]
-prefix = "Style"
-include = [
-  "Appearance",
-  "BreakBetween",
-  "BreakWithin",
-  "BorderStyle",
-  "OutlineStyle",
-  "ComputedFontStretchRange",
-  "ComputedFontStyleDescriptor",
-  "ComputedFontWeightRange",
-  "ComputedTimingFunction",
-  "CursorKind",
-  "Display",
-  "DisplayMode",
-  "PrefersColorScheme",
-  "ExtremumLength",
-  "FillRule",
-  "FontDisplay",
-  "FontFaceSourceListComponent",
-  "FontLanguageOverride",
-  "OverflowWrap",
-  "TimingFunction",
-  "PathCommand",
-  "UnicodeRange",
-  "UserSelect",
-  "Float",
-  "OverscrollBehavior",
-  "ScrollSnapAlign",
-  "ScrollSnapType",
-  "OverflowAnchor",
-  "OverflowClipBox",
-  "Resize",
-  "Overflow",
-  "LengthPercentage",
-  "LetterSpacing",
-  "NonNegativeLengthPercentage",
-  "LengthPercentageOrAuto",
-  "LineHeight",
-  "NonNegativeLengthPercentageOrAuto",
-  "Rect",
-  "IntersectionObserverRootMargin",
-  "Size",
-  "MaxSize",
-  "FlexBasis",
-  "Position",
-  "BackgroundSize",
-  "BorderImageSlice",
-  "BorderSpacing",
-  "BorderRadius",
-  "NonNegativeLengthOrNumberRect",
-  "Perspective",
-  "ZIndex",
-  "TransformOrigin",
-  "WordBreak",
-  "Contain",
-  "RestyleHint",
-  "TouchAction",
-  "WillChangeBits",
-  "TextDecorationLine",
-  "MozListReversed",
-  "Owned",
-  "OwnedOrNull",
-  "Strong",
-]
-item_types = ["enums", "structs", "typedefs"]
-
-[export.body]
-"CSSPixelLength" = """
-  inline nscoord ToAppUnits() const;
-  inline bool IsZero() const;
-"""
-
-"LengthPercentage" = """
-  // Defined in nsStyleCoord.h
-  static constexpr inline StyleLengthPercentage Zero();
-  static inline StyleLengthPercentage FromAppUnits(nscoord);
-  static inline StyleLengthPercentage FromPixels(CSSCoord);
-  static inline StyleLengthPercentage FromPercentage(float);
-  inline CSSCoord LengthInCSSPixels() const;
-  inline float Percentage() const;
-  inline bool HasPercent() const;
-  inline bool ConvertsToLength() const;
-  inline nscoord ToLength() const;
-  inline bool ConvertsToPercentage() const;
-  inline bool HasLengthAndPercentage() const;
-  inline float ToPercentage() const;
-  inline bool IsDefinitelyZero() const;
-  inline CSSCoord ResolveToCSSPixels(CSSCoord aPercentageBasisInCSSPixels) const;
-  template<typename T> inline CSSCoord ResolveToCSSPixelsWith(T aPercentageGetter) const;
-  template<typename T, typename U>
-  inline nscoord Resolve(T aPercentageGetter, U aPercentRoundingFunction) const;
-  template<typename T>
-  inline nscoord Resolve(nscoord aPercentageBasis, T aPercentRoundingFunction) const;
-  template<typename T> inline nscoord Resolve(T aPercentageGetter) const;
-  inline nscoord Resolve(nscoord aPercentageBasis) const;
-"""
-
-"GenericLengthPercentageOrAuto" = """
-  inline bool ConvertsToLength() const;
-  inline nscoord ToLength() const;
-  inline bool ConvertsToPercentage() const;
-  inline float ToPercentage() const;
-  inline bool HasPercent() const;
-  inline bool HasLengthAndPercentage() const;
-"""
-
-"GenericSize" = """
-  inline bool ConvertsToLength() const;
-  inline nscoord ToLength() const;
-  inline bool ConvertsToPercentage() const;
-  inline float ToPercentage() const;
-  inline bool HasPercent() const;
-  inline bool HasLengthAndPercentage() const;
-  inline bool BehavesLikeInitialValueOnBlockAxis() const;
-"""
-
-"GenericFlexBasis" = """
-  inline bool IsAuto() const;
-"""
-
-"GenericMaxSize" = """
-  inline bool ConvertsToLength() const;
-  inline nscoord ToLength() const;
-  inline bool ConvertsToPercentage() const;
-  inline float ToPercentage() const;
-  inline bool HasPercent() const;
-  inline bool HasLengthAndPercentage() const;
-  inline bool BehavesLikeInitialValueOnBlockAxis() const;
-"""
-
-"GenericPosition" = """
-  inline bool DependsOnPositioningAreaSize() const;
-  static inline StyleGenericPosition FromPercentage(float);
-"""
-
-"GenericBackgroundSize" = """
-  bool IsInitialValue() const;
-"""
-
-"Rect" = """
-  // Defined in nsStyleCoord.h
-  template<typename Predicate> inline bool All(Predicate) const;
-  template<typename Predicate> inline bool Any(Predicate) const;
-
-  // Defined in WritingModes.h
-  inline const T& Get(mozilla::Side) const;
-  inline const T& Get(mozilla::WritingMode, mozilla::LogicalSide) const;
-  inline const T& GetIStart(mozilla::WritingMode) const;
-  inline const T& GetBStart(mozilla::WritingMode) const;
-  inline const T& GetIEnd(mozilla::WritingMode) const;
-  inline const T& GetBEnd(mozilla::WritingMode) const;
-"""
-
-"GenericBorderRadius" = """
-  inline const StyleLengthPercentage& Get(mozilla::HalfCorner) const;
-"""
-
-"RestyleHint" = """
-  static inline StyleRestyleHint RestyleSubtree();
-  static inline StyleRestyleHint RecascadeSubtree();
-  static inline StyleRestyleHint ForAnimations();
-"""
-
-# TODO(emilio): Add hooks to cbindgen to be able to generate MOZ_MUST_USE_TYPE
-# or MOZ_MUST_USE on the functions.
-"Owned" = """
-  UniquePtr<GeckoType> Consume() {
-    UniquePtr<GeckoType> ret(ptr);
-    ptr = nullptr;
-    return ret;
-  }
-"""
-
-"OwnedOrNull" = """
-  UniquePtr<GeckoType> Consume() {
-    UniquePtr<GeckoType> ret(ptr);
-    ptr = nullptr;
-    return ret;
-  }
-"""
-
-"Strong" = """
-  already_AddRefed<GeckoType> Consume() {
-    already_AddRefed<GeckoType> ret(const_cast<GeckoType*>(ptr));
-    ptr = nullptr;
-    return ret;
-  }
-"""
diff --git a/components/style/gecko_bindings/sugar/ownership.rs b/components/style/gecko_bindings/sugar/ownership.rs
index 04fbf2e55c8..5170b7dbc5a 100644
--- a/components/style/gecko_bindings/sugar/ownership.rs
+++ b/components/style/gecko_bindings/sugar/ownership.rs
@@ -65,6 +65,14 @@ pub unsafe trait HasBoxFFI: HasSimpleFFI {
     fn into_ffi(self: Box<Self>) -> Owned<Self::FFIType> {
         unsafe { transmute(self) }
     }
+
+    /// Drops an owned FFI pointer. This conceptually takes the
+    /// Owned<Self::FFIType>, except it's a bit of a paint to do that without
+    /// much benefit.
+    #[inline]
+    unsafe fn drop_ffi(ptr: *mut Self::FFIType) {
+        let _ = Box::from_raw(ptr as *mut Self);
+    }
 }
 
 /// Helper trait for conversions between FFI Strong/Borrowed types and Arcs
@@ -268,14 +276,6 @@ pub struct Owned<GeckoType> {
 }
 
 impl<GeckoType> Owned<GeckoType> {
-    /// Gets this `Owned` type as a `Box<ServoType>`.
-    pub fn into_box<ServoType>(self) -> Box<ServoType>
-    where
-        ServoType: HasBoxFFI<FFIType = GeckoType>,
-    {
-        unsafe { transmute(self) }
-    }
-
     /// Converts this instance to a (non-null) instance of `OwnedOrNull`.
     pub fn maybe(self) -> OwnedOrNull<GeckoType> {
         unsafe { transmute(self) }

From c49a88ec84defc10e6a3202bd8f8257fc700de86 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Emilio=20Cobos=20=C3=81lvarez?= <emilio@crisal.io>
Date: Mon, 1 Apr 2019 21:47:43 +0000
Subject: [PATCH 26/59] style: Trivially cleanup and remove some dead font
 code.

Differential Revision: https://phabricator.services.mozilla.com/D24271
---
 components/style/values/specified/font.rs | 14 ++------------
 1 file changed, 2 insertions(+), 12 deletions(-)

diff --git a/components/style/values/specified/font.rs b/components/style/values/specified/font.rs
index fb4fa805212..03896bc9c0b 100644
--- a/components/style/values/specified/font.rs
+++ b/components/style/values/specified/font.rs
@@ -530,18 +530,8 @@ impl FontFamily {
 
     /// Parse a specified font-family value
     pub fn parse_specified<'i, 't>(input: &mut Parser<'i, 't>) -> Result<Self, ParseError<'i>> {
-        input
-            .parse_comma_separated(|input| SingleFontFamily::parse(input))
-            .map(|v| FontFamily::Values(FontFamilyList::new(v.into_boxed_slice())))
-    }
-
-    #[cfg(feature = "gecko")]
-    /// Return the generic ID if it is a single generic font
-    pub fn single_generic(&self) -> Option<u8> {
-        match *self {
-            FontFamily::Values(ref values) => values.single_generic(),
-            _ => None,
-        }
+        let values = input.parse_comma_separated(SingleFontFamily::parse)?;
+        Ok(FontFamily::Values(FontFamilyList::new(values.into_boxed_slice())))
     }
 }
 

From 2184e3f2e55c152ffcc876734182d1ae50e8c6b8 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Emilio=20Cobos=20=C3=81lvarez?= <emilio@crisal.io>
Date: Mon, 1 Apr 2019 21:47:59 +0000
Subject: [PATCH 27/59] style: Cleanup generic font-family handling.

To be more similar between Rust and C++. This introduces GenericFontFamily and
exposes that plus FontFamilyNameSyntax to C++, using that where appropriate
instead of plain uint8_t as we were doing.

As a follow-up, as discussed on IRC with Jonathan, we can remove the -moz-fixed
family, and turn it just into an alias of Monospace.

The only non-trivial change is the MatchType changes, but they're ok I think.
The code already assumed at most one CSS generic, and the struct still takes 8
bits. I've verified that the relevant tests are passing (though try is closed).

Differential Revision: https://phabricator.services.mozilla.com/D24272
---
 components/style/font_metrics.rs              |   2 +-
 components/style/gecko/wrapper.rs             |  22 +-
 components/style/properties/cascade.rs        |  11 +-
 components/style/properties/gecko.mako.rs     |  30 +-
 .../style/properties/longhands/font.mako.rs   |   4 +-
 components/style/values/computed/font.rs      | 302 ++++++------------
 components/style/values/specified/font.rs     |   3 +-
 7 files changed, 124 insertions(+), 250 deletions(-)

diff --git a/components/style/font_metrics.rs b/components/style/font_metrics.rs
index 15b5fd453e8..ab2468e5439 100644
--- a/components/style/font_metrics.rs
+++ b/components/style/font_metrics.rs
@@ -43,7 +43,7 @@ pub trait FontMetricsProvider {
     }
 
     /// Get default size of a given language and generic family.
-    fn get_size(&self, font_name: &Atom, font_family: u8) -> Au;
+    fn get_size(&self, font_name: &Atom, font_family: crate::values::computed::font::GenericFontFamily) -> Au;
 
     /// Construct from a shared style context
     fn create_from(context: &SharedStyleContext) -> Self
diff --git a/components/style/gecko/wrapper.rs b/components/style/gecko/wrapper.rs
index 46eaa427b3a..a3c1ebeec0b 100644
--- a/components/style/gecko/wrapper.rs
+++ b/components/style/gecko/wrapper.rs
@@ -69,6 +69,7 @@ use crate::selector_parser::{AttrValue, HorizontalDirection, Lang};
 use crate::shared_lock::Locked;
 use crate::string_cache::{Atom, Namespace, WeakAtom, WeakNamespace};
 use crate::stylist::CascadeData;
+use crate::values::computed::font::GenericFontFamily;
 use crate::values::specified::length::FontBaseSize;
 use crate::CaseSensitivityExt;
 use app_units::Au;
@@ -1041,7 +1042,7 @@ impl FontMetricsProvider for GeckoFontMetricsProvider {
         GeckoFontMetricsProvider::new()
     }
 
-    fn get_size(&self, font_name: &Atom, font_family: u8) -> Au {
+    fn get_size(&self, font_name: &Atom, font_family: GenericFontFamily) -> Au {
         let mut cache = self.font_size_cache.borrow_mut();
         if let Some(sizes) = cache.iter().find(|el| el.0 == *font_name) {
             return sizes.1.size_for_generic(font_family);
@@ -1100,16 +1101,17 @@ impl FontMetricsProvider for GeckoFontMetricsProvider {
 }
 
 impl structs::FontSizePrefs {
-    fn size_for_generic(&self, font_family: u8) -> Au {
+    fn size_for_generic(&self, font_family: GenericFontFamily) -> Au {
         Au(match font_family {
-            structs::kPresContext_DefaultVariableFont_ID => self.mDefaultVariableSize,
-            structs::kPresContext_DefaultFixedFont_ID => self.mDefaultFixedSize,
-            structs::kGenericFont_serif => self.mDefaultSerifSize,
-            structs::kGenericFont_sans_serif => self.mDefaultSansSerifSize,
-            structs::kGenericFont_monospace => self.mDefaultMonospaceSize,
-            structs::kGenericFont_cursive => self.mDefaultCursiveSize,
-            structs::kGenericFont_fantasy => self.mDefaultFantasySize,
-            _ => unreachable!("Unknown generic ID"),
+            GenericFontFamily::None => self.mDefaultVariableSize,
+            GenericFontFamily::Serif => self.mDefaultSerifSize,
+            GenericFontFamily::SansSerif => self.mDefaultSansSerifSize,
+            GenericFontFamily::Monospace => self.mDefaultMonospaceSize,
+            GenericFontFamily::Cursive => self.mDefaultCursiveSize,
+            GenericFontFamily::Fantasy => self.mDefaultFantasySize,
+            GenericFontFamily::MozEmoji => {
+                unreachable!("Should never get here, since this doesn't (yet) appear on font family")
+            },
         })
     }
 }
diff --git a/components/style/properties/cascade.rs b/components/style/properties/cascade.rs
index 7d4c8c6275c..1b76aefdd74 100644
--- a/components/style/properties/cascade.rs
+++ b/components/style/properties/cascade.rs
@@ -683,6 +683,7 @@ impl<'a, 'b: 'a> Cascade<'a, 'b> {
     #[cfg(feature = "gecko")]
     fn recompute_default_font_family_type_if_needed(&mut self) {
         use crate::gecko_bindings::{bindings, structs};
+        use crate::values::computed::font::GenericFontFamily;
 
         if !self.seen.contains(LonghandId::XLang) &&
            !self.seen.contains(LonghandId::FontFamily) {
@@ -697,7 +698,7 @@ impl<'a, 'b: 'a> Cascade<'a, 'b> {
             // System fonts are all right, and should have the default font type
             // set to none already, so bail out early.
             if font.mFont.systemFont {
-                debug_assert_eq!(font.mFont.fontlist.mDefaultFontType, structs::FontFamilyType::eFamily_none);
+                debug_assert_eq!(font.mFont.fontlist.mDefaultFontType, GenericFontFamily::None);
                 return;
             }
 
@@ -717,11 +718,11 @@ impl<'a, 'b: 'a> Cascade<'a, 'b> {
                 !use_document_fonts &&
                 matches!(
                     font.mGenericID,
-                    structs::kGenericFont_NONE |
-                    structs::kGenericFont_fantasy |
-                    structs::kGenericFont_cursive
+                    GenericFontFamily::None |
+                    GenericFontFamily::Fantasy |
+                    GenericFontFamily::Cursive
                 ) &&
-                default_font_type != structs::FontFamilyType::eFamily_none;
+                default_font_type != GenericFontFamily::None;
 
             if !prioritize_user_fonts && default_font_type == font.mFont.fontlist.mDefaultFontType {
                 // Nothing to do.
diff --git a/components/style/properties/gecko.mako.rs b/components/style/properties/gecko.mako.rs
index 17f10cd4552..3bb8264bf09 100644
--- a/components/style/properties/gecko.mako.rs
+++ b/components/style/properties/gecko.mako.rs
@@ -1984,20 +1984,20 @@ fn static_assert() {
     <% impl_font_settings("font_variation_settings", "gfxFontVariation", "VariationValue", "f32", "f32") %>
 
     pub fn set_font_family(&mut self, v: longhands::font_family::computed_value::T) {
-        use crate::gecko_bindings::structs::FontFamilyType;
+        use crate::values::computed::font::GenericFontFamily;
 
         let is_system_font = v.is_system_font;
         self.gecko.mFont.systemFont = is_system_font;
         self.gecko.mGenericID = if is_system_font {
-            structs::kGenericFont_NONE
+            GenericFontFamily::None
         } else {
-            v.families.single_generic().unwrap_or(structs::kGenericFont_NONE)
+            v.families.single_generic().unwrap_or(GenericFontFamily::None)
         };
         self.gecko.mFont.fontlist.mFontlist.mBasePtr.set_move(
             v.families.shared_font_list().clone()
         );
         // Fixed-up if needed in Cascade::fixup_font_stuff.
-        self.gecko.mFont.fontlist.mDefaultFontType = FontFamilyType::eFamily_none;
+        self.gecko.mFont.fontlist.mDefaultFontType = GenericFontFamily::None;
     }
 
     pub fn copy_font_family_from(&mut self, other: &Self) {
@@ -2011,33 +2011,13 @@ fn static_assert() {
     }
 
     pub fn clone_font_family(&self) -> longhands::font_family::computed_value::T {
-        use crate::gecko_bindings::structs::FontFamilyType;
         use crate::values::computed::font::{FontFamily, SingleFontFamily, FontFamilyList};
 
         let fontlist = &self.gecko.mFont.fontlist;
         let shared_fontlist = unsafe { fontlist.mFontlist.mBasePtr.to_safe() };
 
         let families = if shared_fontlist.mNames.is_empty() {
-            let default = fontlist.mDefaultFontType;
-            let default = match default {
-                FontFamilyType::eFamily_serif => {
-                    SingleFontFamily::Generic(atom!("serif"))
-                }
-                _ => {
-                    // This can break with some combinations of user prefs, see
-                    // bug 1442195 for example. It doesn't really matter in this
-                    // case...
-                    //
-                    // FIXME(emilio): Probably should be storing the whole
-                    // default font name instead though.
-                    debug_assert_eq!(
-                        default,
-                        FontFamilyType::eFamily_sans_serif,
-                        "Default generic should be serif or sans-serif"
-                    );
-                    SingleFontFamily::Generic(atom!("sans-serif"))
-                }
-            };
+            let default = SingleFontFamily::Generic(fontlist.mDefaultFontType);
             FontFamilyList::new(Box::new([default]))
         } else {
             FontFamilyList::SharedFontList(shared_fontlist)
diff --git a/components/style/properties/longhands/font.mako.rs b/components/style/properties/longhands/font.mako.rs
index a2eb9c3dcff..b253fde0b8d 100644
--- a/components/style/properties/longhands/font.mako.rs
+++ b/components/style/properties/longhands/font.mako.rs
@@ -326,7 +326,7 @@ ${helpers.predefined_type(
 
         use app_units::Au;
         use cssparser::{Parser, ToCss};
-        use crate::gecko_bindings::structs::FontFamilyType;
+        use crate::values::computed::font::GenericFontFamily;
         use crate::properties::longhands;
         use std::fmt;
         use std::hash::{Hash, Hasher};
@@ -466,7 +466,7 @@ ${helpers.predefined_type(
                 pub ${name}: longhands::${name}::computed_value::T,
             % endfor
             pub system_font: SystemFont,
-            pub default_font_type: FontFamilyType,
+            pub default_font_type: GenericFontFamily,
         }
 
         impl SystemFont {
diff --git a/components/style/values/computed/font.rs b/components/style/values/computed/font.rs
index 6bd8cae445b..c1d2f1b7425 100644
--- a/components/style/values/computed/font.rs
+++ b/components/style/values/computed/font.rs
@@ -157,10 +157,6 @@ impl FontSize {
     }
 }
 
-/// XXXManishearth it might be better to
-/// animate this as computed, however this complicates
-/// clamping and might not be the right thing to do.
-/// We should figure it out.
 impl ToAnimatedValue for FontSize {
     type AnimatedValue = NonNegativeLength;
 
@@ -178,8 +174,8 @@ impl ToAnimatedValue for FontSize {
     }
 }
 
-#[derive(Clone, Debug, Eq, Hash, PartialEq)]
-#[cfg_attr(feature = "servo", derive(MallocSizeOf))]
+#[derive(Clone, Debug, Eq, PartialEq)]
+#[cfg_attr(feature = "servo", derive(Hash, MallocSizeOf))]
 /// Specifies a prioritized list of font family names or generic family names.
 pub struct FontFamily {
     /// The actual list of family names.
@@ -193,7 +189,7 @@ impl FontFamily {
     /// Get default font family as `serif` which is a generic font-family
     pub fn serif() -> Self {
         FontFamily {
-            families: FontFamilyList::new(Box::new([SingleFontFamily::Generic(atom!("serif"))])),
+            families: FontFamilyList::new(Box::new([SingleFontFamily::Generic(GenericFontFamily::Serif)])),
             is_system_font: false,
         }
     }
@@ -232,7 +228,7 @@ pub struct FamilyName {
     /// Name of the font family
     pub name: Atom,
     /// Syntax of the font family
-    pub syntax: FamilyNameSyntax,
+    pub syntax: FontFamilyNameSyntax,
 }
 
 impl ToCss for FamilyName {
@@ -241,12 +237,12 @@ impl ToCss for FamilyName {
         W: fmt::Write,
     {
         match self.syntax {
-            FamilyNameSyntax::Quoted => {
+            FontFamilyNameSyntax::Quoted => {
                 dest.write_char('"')?;
                 write!(CssStringWriter::new(dest), "{}", self.name)?;
                 dest.write_char('"')
             },
-            FamilyNameSyntax::Identifiers => {
+            FontFamilyNameSyntax::Identifiers => {
                 let mut first = true;
                 for ident in self.name.to_string().split(' ') {
                     if first {
@@ -268,11 +264,12 @@ impl ToCss for FamilyName {
     }
 }
 
-#[derive(Clone, Debug, Eq, Hash, MallocSizeOf, PartialEq, ToShmem)]
+#[derive(Clone, Copy, Debug, Eq, Hash, MallocSizeOf, PartialEq, ToShmem)]
 #[cfg_attr(feature = "servo", derive(Deserialize, Serialize))]
 /// Font family names must either be given quoted as strings,
 /// or unquoted as a sequence of one or more identifiers.
-pub enum FamilyNameSyntax {
+#[repr(u8)]
+pub enum FontFamilyNameSyntax {
     /// The family name was specified in a quoted form, e.g. "Font Name"
     /// or 'Font Name'.
     Quoted,
@@ -282,85 +279,79 @@ pub enum FamilyNameSyntax {
     Identifiers,
 }
 
-#[derive(Clone, Debug, Eq, Hash, MallocSizeOf, PartialEq)]
-#[cfg_attr(feature = "servo", derive(Deserialize, Serialize))]
+#[derive(Clone, Debug, Eq, MallocSizeOf, PartialEq, ToCss)]
+#[cfg_attr(feature = "servo", derive(Deserialize, Serialize, Hash))]
 /// A set of faces that vary in weight, width or slope.
 pub enum SingleFontFamily {
     /// The name of a font family of choice.
     FamilyName(FamilyName),
     /// Generic family name.
-    Generic(Atom),
+    Generic(GenericFontFamily),
+}
+
+/// A generic font-family name.
+///
+/// The order here is important, if you change it make sure that
+/// `gfxPlatformFontList.h`s ranged array and `gfxFontFamilyList`'s
+/// sSingleGenerics are updated as well.
+#[derive(Clone, Copy, Debug, Eq, Hash, MallocSizeOf, PartialEq, Parse, ToCss)]
+#[repr(u8)]
+#[allow(missing_docs)]
+pub enum GenericFontFamily {
+    /// No generic family specified, only for internal usage.
+    #[css(skip)]
+    None,
+    Serif,
+    SansSerif,
+    Monospace,
+    Cursive,
+    Fantasy,
+    /// This is basically monospace, but with different font prefs. We should
+    /// consider removing it in favor of just using the monospace.* prefs, since
+    /// in practice we don't override the monospace prefs at all.
+    #[cfg(feature = "gecko")]
+    MozFixed,
+    /// An internal value for emoji font selection.
+    #[css(skip)]
+    #[cfg(feature = "gecko")]
+    MozEmoji,
+}
+
+// TODO(emilio): Derive this when we make -moz-fixed a parse alias of Monospace.
+impl ToCss for GenericFontFamily {
+    fn to_css<W>(&self, dest: &mut CssWriter<W>) -> fmt::Result
+    where
+        W: fmt::Write,
+    {
+        dest.write_str(match *self {
+            GenericFontFamily::MozEmoji |
+            GenericFontFamily::Default => return Ok(()),
+            GenericFontFamily::MozFixed |
+            GenericFontFamily::Monospace => "monospace",
+            GenericFontFamily::Serif => "serif",
+            GenericFontFamily::SansSerif => "sans-serif",
+            GenericFontFamily::Cursive => "cursive",
+            GenericFontFamily::Fantasy => "fantasy",
+        })
+    }
 }
 
 impl SingleFontFamily {
-    #[inline]
-    /// Get font family name as Atom
-    pub fn atom(&self) -> &Atom {
-        match *self {
-            SingleFontFamily::FamilyName(ref family_name) => &family_name.name,
-            SingleFontFamily::Generic(ref name) => name,
-        }
-    }
-
-    #[inline]
-    #[cfg(not(feature = "gecko"))] // Gecko can't borrow atoms as UTF-8.
-    /// Get font family name
-    pub fn name(&self) -> &str {
-        self.atom()
-    }
-
-    #[cfg(not(feature = "gecko"))] // Gecko can't borrow atoms as UTF-8.
-    /// Get the corresponding font-family with Atom
-    pub fn from_atom(input: Atom) -> SingleFontFamily {
-        match input {
-            atom!("serif") |
-            atom!("sans-serif") |
-            atom!("cursive") |
-            atom!("fantasy") |
-            atom!("monospace") => return SingleFontFamily::Generic(input),
-            _ => {},
-        }
-        match_ignore_ascii_case! { &input,
-            "serif" => return SingleFontFamily::Generic(atom!("serif")),
-            "sans-serif" => return SingleFontFamily::Generic(atom!("sans-serif")),
-            "cursive" => return SingleFontFamily::Generic(atom!("cursive")),
-            "fantasy" => return SingleFontFamily::Generic(atom!("fantasy")),
-            "monospace" => return SingleFontFamily::Generic(atom!("monospace")),
-            _ => {}
-        }
-
-        // We don't know if it's quoted or not. So we set it to
-        // quoted by default.
-        SingleFontFamily::FamilyName(FamilyName {
-            name: input,
-            syntax: FamilyNameSyntax::Quoted,
-        })
-    }
-
-    /// Parse a font-family value
+    /// Parse a font-family value.
     pub fn parse<'i, 't>(input: &mut Parser<'i, 't>) -> Result<Self, ParseError<'i>> {
         if let Ok(value) = input.try(|i| i.expect_string_cloned()) {
             return Ok(SingleFontFamily::FamilyName(FamilyName {
                 name: Atom::from(&*value),
-                syntax: FamilyNameSyntax::Quoted,
+                syntax: FontFamilyNameSyntax::Quoted,
             }));
         }
-        let first_ident = input.expect_ident()?.clone();
 
-        // FIXME(bholley): The fast thing to do here would be to look up the
-        // string (as lowercase) in the static atoms table. We don't have an
-        // API to do that yet though, so we do the simple thing for now.
-        let mut css_wide_keyword = false;
-        match_ignore_ascii_case! { &first_ident,
-            "serif" => return Ok(SingleFontFamily::Generic(atom!("serif"))),
-            "sans-serif" => return Ok(SingleFontFamily::Generic(atom!("sans-serif"))),
-            "cursive" => return Ok(SingleFontFamily::Generic(atom!("cursive"))),
-            "fantasy" => return Ok(SingleFontFamily::Generic(atom!("fantasy"))),
-            "monospace" => return Ok(SingleFontFamily::Generic(atom!("monospace"))),
-
-            #[cfg(feature = "gecko")]
-            "-moz-fixed" => return Ok(SingleFontFamily::Generic(atom!("-moz-fixed"))),
+        let first_ident = input.expect_ident_cloned()?;
+        if let Ok(generic) = GenericFontFamily::from_ident(&first_ident) {
+            return Ok(SingleFontFamily::Generic(generic));
+        }
 
+        let reserved = match_ignore_ascii_case! { &first_ident,
             // https://drafts.csswg.org/css-fonts/#propdef-font-family
             // "Font family names that happen to be the same as a keyword value
             //  (`inherit`, `serif`, `sans-serif`, `monospace`, `fantasy`, and `cursive`)
@@ -368,18 +359,15 @@ impl SingleFontFamily {
             //  The keywords ‘initial’ and ‘default’ are reserved for future use
             //  and must also be quoted when used as font names.
             //  UAs must not consider these keywords as matching the <family-name> type."
-            "inherit" => css_wide_keyword = true,
-            "initial" => css_wide_keyword = true,
-            "unset" => css_wide_keyword = true,
-            "default" => css_wide_keyword = true,
-            _ => {}
-        }
+            "inherit" | "initial" | "unset" | "revert" | "default" => true,
+            _ => false,
+        };
 
         let mut value = first_ident.as_ref().to_owned();
 
         // These keywords are not allowed by themselves.
         // The only way this value can be valid with with another keyword.
-        if css_wide_keyword {
+        if reserved {
             let ident = input.expect_ident()?;
             value.push(' ');
             value.push_str(&ident);
@@ -393,9 +381,9 @@ impl SingleFontFamily {
             // `font-family: \ a\ \ b\ \ c\ ;`, it is tricky to serialize them
             // as identifiers correctly. Just mark them quoted so we don't need
             // to worry about them in serialization code.
-            FamilyNameSyntax::Quoted
+            FontFamilyNameSyntax::Quoted
         } else {
-            FamilyNameSyntax::Identifiers
+            FontFamilyNameSyntax::Identifiers
         };
         Ok(SingleFontFamily::FamilyName(FamilyName {
             name: Atom::from(value),
@@ -403,94 +391,18 @@ impl SingleFontFamily {
         }))
     }
 
-    #[cfg(feature = "gecko")]
-    /// Return the generic ID for a given generic font name
-    pub fn generic(name: &Atom) -> (structs::FontFamilyType, u8) {
-        use crate::gecko_bindings::structs::FontFamilyType;
-        if *name == atom!("serif") {
-            (FontFamilyType::eFamily_serif, structs::kGenericFont_serif)
-        } else if *name == atom!("sans-serif") {
-            (
-                FontFamilyType::eFamily_sans_serif,
-                structs::kGenericFont_sans_serif,
-            )
-        } else if *name == atom!("cursive") {
-            (
-                FontFamilyType::eFamily_cursive,
-                structs::kGenericFont_cursive,
-            )
-        } else if *name == atom!("fantasy") {
-            (
-                FontFamilyType::eFamily_fantasy,
-                structs::kGenericFont_fantasy,
-            )
-        } else if *name == atom!("monospace") {
-            (
-                FontFamilyType::eFamily_monospace,
-                structs::kGenericFont_monospace,
-            )
-        } else if *name == atom!("-moz-fixed") {
-            (
-                FontFamilyType::eFamily_moz_fixed,
-                structs::kGenericFont_moz_fixed,
-            )
-        } else {
-            panic!("Unknown generic {}", name);
-        }
-    }
-
     #[cfg(feature = "gecko")]
     /// Get the corresponding font-family with family name
     fn from_font_family_name(family: &structs::FontFamilyName) -> SingleFontFamily {
-        use crate::gecko_bindings::structs::FontFamilyType;
-
-        match family.mType {
-            FontFamilyType::eFamily_sans_serif => SingleFontFamily::Generic(atom!("sans-serif")),
-            FontFamilyType::eFamily_serif => SingleFontFamily::Generic(atom!("serif")),
-            FontFamilyType::eFamily_monospace => SingleFontFamily::Generic(atom!("monospace")),
-            FontFamilyType::eFamily_cursive => SingleFontFamily::Generic(atom!("cursive")),
-            FontFamilyType::eFamily_fantasy => SingleFontFamily::Generic(atom!("fantasy")),
-            FontFamilyType::eFamily_moz_fixed => SingleFontFamily::Generic(atom!("-moz-fixed")),
-            FontFamilyType::eFamily_named => {
-                let name = unsafe { Atom::from_raw(family.mName.mRawPtr) };
-                SingleFontFamily::FamilyName(FamilyName {
-                    name,
-                    syntax: FamilyNameSyntax::Identifiers,
-                })
-            },
-            FontFamilyType::eFamily_named_quoted => {
-                let name = unsafe { Atom::from_raw(family.mName.mRawPtr) };
-                SingleFontFamily::FamilyName(FamilyName {
-                    name,
-                    syntax: FamilyNameSyntax::Quoted,
-                })
-            },
-            _ => panic!("Found unexpected font FontFamilyType"),
-        }
-    }
-}
-
-impl ToCss for SingleFontFamily {
-    fn to_css<W>(&self, dest: &mut CssWriter<W>) -> fmt::Result
-    where
-        W: fmt::Write,
-    {
-        match *self {
-            SingleFontFamily::FamilyName(ref name) => name.to_css(dest),
-
-            // All generic values accepted by the parser are known to not require escaping.
-            SingleFontFamily::Generic(ref name) => {
-                #[cfg(feature = "gecko")]
-                {
-                    // We should treat -moz-fixed as monospace
-                    if name == &atom!("-moz-fixed") {
-                        return dest.write_str("monospace");
-                    }
-                }
-
-                write!(dest, "{}", name)
-            },
+        if family.mName.mRawPtr.is_null() {
+            debug_assert_ne!(family.mGeneric, GenericFontFamily::None);
+            return SingleFontFamily::Generic(family.mGeneric);
         }
+        let name = unsafe { Atom::from_raw(family.mName.mRawPtr) };
+        SingleFontFamily::FamilyName(FamilyName {
+            name,
+            syntax: family.mSyntax,
+        })
     }
 }
 
@@ -506,7 +418,7 @@ pub enum FontFamilyList {
     /// A strong reference to a Gecko SharedFontList object.
     SharedFontList(RefPtr<structs::SharedFontList>),
     /// A font-family generic ID.
-    Generic(structs::FontFamilyType),
+    Generic(GenericFontFamily),
 }
 
 #[cfg(feature = "gecko")]
@@ -514,38 +426,19 @@ impl ToShmem for FontFamilyList {
     fn to_shmem(&self, _builder: &mut SharedMemoryBuilder) -> ManuallyDrop<Self> {
         // In practice, the only SharedFontList objects we create from shared
         // style sheets are ones with a single generic entry.
-        ManuallyDrop::new(match self {
-            FontFamilyList::SharedFontList(r) => {
+        ManuallyDrop::new(match *self {
+            FontFamilyList::SharedFontList(ref r) => {
                 assert!(
                     r.mNames.len() == 1 && r.mNames[0].mName.mRawPtr.is_null(),
                     "ToShmem failed for FontFamilyList: cannot handle non-generic families",
                 );
-                FontFamilyList::Generic(r.mNames[0].mType)
+                FontFamilyList::Generic(r.mNames[0].mGeneric)
             },
-            FontFamilyList::Generic(t) => FontFamilyList::Generic(*t),
+            FontFamilyList::Generic(t) => FontFamilyList::Generic(t),
         })
     }
 }
 
-#[cfg(feature = "gecko")]
-impl Hash for FontFamilyList {
-    fn hash<H>(&self, state: &mut H)
-    where
-        H: Hasher,
-    {
-        use crate::string_cache::WeakAtom;
-
-        for name in self.shared_font_list().mNames.iter() {
-            name.mType.hash(state);
-            if !name.mName.mRawPtr.is_null() {
-                unsafe {
-                    WeakAtom::new(name.mName.mRawPtr).hash(state);
-                }
-            }
-        }
-    }
-}
-
 #[cfg(feature = "gecko")]
 impl PartialEq for FontFamilyList {
     fn eq(&self, other: &FontFamilyList) -> bool {
@@ -556,7 +449,8 @@ impl PartialEq for FontFamilyList {
             return false;
         }
         for (a, b) in self_list.mNames.iter().zip(other_list.mNames.iter()) {
-            if a.mType != b.mType || a.mName.mRawPtr != b.mName.mRawPtr {
+            if a.mSyntax != b.mSyntax || a.mName.mRawPtr != b.mName.mRawPtr ||
+                a.mGeneric != b.mGeneric {
                 return false;
             }
         }
@@ -588,19 +482,17 @@ impl FontFamilyList {
         for family in families.iter() {
             match *family {
                 SingleFontFamily::FamilyName(ref f) => {
-                    let quoted = matches!(f.syntax, FamilyNameSyntax::Quoted);
                     unsafe {
                         bindings::Gecko_nsTArray_FontFamilyName_AppendNamed(
                             names,
                             f.name.as_ptr(),
-                            quoted,
+                            f.syntax,
                         );
                     }
                 },
-                SingleFontFamily::Generic(ref name) => {
-                    let (family_type, _generic) = SingleFontFamily::generic(name);
+                SingleFontFamily::Generic(family) => {
                     unsafe {
-                        bindings::Gecko_nsTArray_FontFamilyName_AppendGeneric(names, family_type);
+                        bindings::Gecko_nsTArray_FontFamilyName_AppendGeneric(names, family);
                     }
                 },
             }
@@ -625,12 +517,11 @@ impl FontFamilyList {
     }
 
     /// Return the generic ID if it is a single generic font
-    #[cfg(feature = "gecko")]
-    pub fn single_generic(&self) -> Option<u8> {
+    pub fn single_generic(&self) -> Option<GenericFontFamily> {
         let mut iter = self.iter();
-        if let Some(SingleFontFamily::Generic(ref name)) = iter.next() {
+        if let Some(SingleFontFamily::Generic(f)) = iter.next() {
             if iter.next().is_none() {
-                return Some(SingleFontFamily::generic(name).1);
+                return Some(f);
             }
         }
         None
@@ -639,13 +530,12 @@ impl FontFamilyList {
     /// Return a reference to the Gecko SharedFontList.
     #[cfg(feature = "gecko")]
     pub fn shared_font_list(&self) -> &RefPtr<structs::SharedFontList> {
-        match self {
-            FontFamilyList::SharedFontList(r) => r,
+        match *self {
+            FontFamilyList::SharedFontList(ref r) => r,
             FontFamilyList::Generic(t) => {
                 unsafe {
                     // TODO(heycam): Should really add StaticRefPtr sugar.
-                    let index =
-                        (*t as usize) - (structs::FontFamilyType::eFamily_generic_first as usize);
+                    let index = t as usize;
                     mem::transmute::<
                         &structs::StaticRefPtr<structs::SharedFontList>,
                         &RefPtr<structs::SharedFontList>,
diff --git a/components/style/values/specified/font.rs b/components/style/values/specified/font.rs
index 03896bc9c0b..1e19ebe7a08 100644
--- a/components/style/values/specified/font.rs
+++ b/components/style/values/specified/font.rs
@@ -515,7 +515,8 @@ impl From<LengthPercentage> for FontSize {
 }
 
 /// Specifies a prioritized list of font family names or generic family names.
-#[derive(Clone, Debug, Eq, Hash, PartialEq, ToCss, ToShmem)]
+#[derive(Clone, Debug, Eq, PartialEq, ToCss, ToShmem)]
+#[cfg_attr(feature = "servo", derive(Hash))]
 pub enum FontFamily {
     /// List of `font-family`
     #[css(comma)]

From 0406be7b686a4d5ec9992f5bc8fdc82bc2402d55 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Emilio=20Cobos=20=C3=81lvarez?= <emilio@crisal.io>
Date: Mon, 1 Apr 2019 21:48:08 +0000
Subject: [PATCH 28/59] style: Make the fixed generic family a parse-time alias
 to monospace.

As discussed on IRC, fixed is only used for prefs right now, and:

 * We already copy the fixed size to the monospace font.
 * We already serialize the fixed family as "monospace" in the style system.

So it already works somewhat inconsistently. Making it an alias makes it
work consistently.

Differential Revision: https://phabricator.services.mozilla.com/D24288
---
 components/style/values/computed/font.rs | 25 +-----------------------
 1 file changed, 1 insertion(+), 24 deletions(-)

diff --git a/components/style/values/computed/font.rs b/components/style/values/computed/font.rs
index c1d2f1b7425..d332cf4d873 100644
--- a/components/style/values/computed/font.rs
+++ b/components/style/values/computed/font.rs
@@ -303,39 +303,16 @@ pub enum GenericFontFamily {
     None,
     Serif,
     SansSerif,
+    #[parse(aliases = "-moz-fixed")]
     Monospace,
     Cursive,
     Fantasy,
-    /// This is basically monospace, but with different font prefs. We should
-    /// consider removing it in favor of just using the monospace.* prefs, since
-    /// in practice we don't override the monospace prefs at all.
-    #[cfg(feature = "gecko")]
-    MozFixed,
     /// An internal value for emoji font selection.
     #[css(skip)]
     #[cfg(feature = "gecko")]
     MozEmoji,
 }
 
-// TODO(emilio): Derive this when we make -moz-fixed a parse alias of Monospace.
-impl ToCss for GenericFontFamily {
-    fn to_css<W>(&self, dest: &mut CssWriter<W>) -> fmt::Result
-    where
-        W: fmt::Write,
-    {
-        dest.write_str(match *self {
-            GenericFontFamily::MozEmoji |
-            GenericFontFamily::Default => return Ok(()),
-            GenericFontFamily::MozFixed |
-            GenericFontFamily::Monospace => "monospace",
-            GenericFontFamily::Serif => "serif",
-            GenericFontFamily::SansSerif => "sans-serif",
-            GenericFontFamily::Cursive => "cursive",
-            GenericFontFamily::Fantasy => "fantasy",
-        })
-    }
-}
-
 impl SingleFontFamily {
     /// Parse a font-family value.
     pub fn parse<'i, 't>(input: &mut Parser<'i, 't>) -> Result<Self, ParseError<'i>> {

From c106fb1231a878989101055234e6575965033d8c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Emilio=20Cobos=20=C3=81lvarez?= <emilio@crisal.io>
Date: Tue, 2 Apr 2019 14:47:13 +0200
Subject: [PATCH 29/59] style: Remove comment that is outdated since I fixed it
 in bug 1483808.

---
 components/style/gecko/media_features.rs | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/components/style/gecko/media_features.rs b/components/style/gecko/media_features.rs
index 12417d38ef0..4b94571c8ef 100644
--- a/components/style/gecko/media_features.rs
+++ b/components/style/gecko/media_features.rs
@@ -127,10 +127,6 @@ fn eval_device_aspect_ratio(
 }
 
 /// https://compat.spec.whatwg.org/#css-media-queries-webkit-device-pixel-ratio
-///
-/// FIXME(emilio): This should be an alias of `resolution`, according to the
-/// spec, and also according to the code in Chromium. Unify with
-/// `eval_resolution`.
 fn eval_device_pixel_ratio(
     device: &Device,
     query_value: Option<f32>,

From b268ef6aedbd72646beada815d909d5bd115f4df Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Emilio=20Cobos=20=C3=81lvarez?= <emilio@crisal.io>
Date: Wed, 3 Apr 2019 12:00:44 +0200
Subject: [PATCH 30/59] style: Remove some redundant use statements.

---
 components/style/gecko/conversions.rs    | 13 ++-----------
 components/style/gecko/values.rs         |  1 -
 components/style/gecko/wrapper.rs        |  1 -
 components/style/rule_tree/mod.rs        |  2 +-
 components/style/stylesheet_set.rs       |  2 --
 components/style/traversal.rs            |  3 ---
 components/style/values/generics/font.rs |  2 +-
 7 files changed, 4 insertions(+), 20 deletions(-)

diff --git a/components/style/gecko/conversions.rs b/components/style/gecko/conversions.rs
index e36ff141eae..43438438a40 100644
--- a/components/style/gecko/conversions.rs
+++ b/components/style/gecko/conversions.rs
@@ -418,10 +418,8 @@ impl nsStyleImage {
         use self::structs::NS_STYLE_GRADIENT_SIZE_CLOSEST_SIDE as CLOSEST_SIDE;
         use self::structs::NS_STYLE_GRADIENT_SIZE_FARTHEST_CORNER as FARTHEST_CORNER;
         use self::structs::NS_STYLE_GRADIENT_SIZE_FARTHEST_SIDE as FARTHEST_SIDE;
-        use crate::values::computed::image::LineDirection;
         use crate::values::computed::position::Position;
-        use crate::values::computed::Length;
-        use crate::values::generics::image::{Circle, ColorStop, CompatMode, Ellipse};
+        use crate::values::generics::image::{Circle, ColorStop, Ellipse};
         use crate::values::generics::image::{EndingShape, GradientKind, ShapeExtent};
 
         let gecko_gradient = bindings::Gecko_GetGradientImageValue(self)
@@ -834,8 +832,7 @@ impl TrackSize<LengthPercentage> {
     /// Return TrackSize from given two nsStyleCoord
     pub fn from_gecko_style_coords<T: CoordData>(gecko_min: &T, gecko_max: &T) -> Self {
         use crate::gecko_bindings::structs::root::nsStyleUnit;
-        use crate::values::computed::length::LengthPercentage;
-        use crate::values::generics::grid::{TrackBreadth, TrackSize};
+        use crate::values::generics::grid::TrackBreadth;
 
         if gecko_min.unit() == nsStyleUnit::eStyleUnit_None {
             debug_assert!(
@@ -862,8 +859,6 @@ impl TrackSize<LengthPercentage> {
 
     /// Save TrackSize to given gecko fields.
     pub fn to_gecko_style_coords<T: CoordDataMut>(&self, gecko_min: &mut T, gecko_max: &mut T) {
-        use crate::values::generics::grid::TrackSize;
-
         match *self {
             TrackSize::FitContent(ref lop) => {
                 // Gecko sets min value to None and max value to the actual value in fit-content
@@ -893,8 +888,6 @@ impl TrackListValue<LengthPercentage, Integer> {
 
     /// Save TrackSize to given gecko fields.
     pub fn to_gecko_style_coords<T: CoordDataMut>(&self, gecko_min: &mut T, gecko_max: &mut T) {
-        use crate::values::generics::grid::TrackListValue;
-
         match *self {
             TrackListValue::TrackSize(ref size) => size.to_gecko_style_coords(gecko_min, gecko_max),
             _ => unreachable!("Should only transform from track-size computed values"),
@@ -918,8 +911,6 @@ where
     pub fn from_gecko_rect(
         sides: &crate::gecko_bindings::structs::nsStyleSides,
     ) -> Option<crate::values::generics::rect::Rect<T>> {
-        use crate::values::generics::rect::Rect;
-
         Some(Rect::new(
             T::from_gecko_style_coord(&sides.data_at(0)).expect("coord[0] cound not convert"),
             T::from_gecko_style_coord(&sides.data_at(1)).expect("coord[1] cound not convert"),
diff --git a/components/style/gecko/values.rs b/components/style/gecko/values.rs
index 6b3e7a676e0..946fa437d64 100644
--- a/components/style/gecko/values.rs
+++ b/components/style/gecko/values.rs
@@ -317,7 +317,6 @@ impl GeckoStyleCoordConvertible for ScrollSnapPoint<LengthPercentage> {
 
     fn from_gecko_style_coord<T: CoordData>(coord: &T) -> Option<Self> {
         use crate::gecko_bindings::structs::root::nsStyleUnit;
-        use crate::values::generics::gecko::ScrollSnapPoint;
 
         Some(match coord.unit() {
             nsStyleUnit::eStyleUnit_None => ScrollSnapPoint::None,
diff --git a/components/style/gecko/wrapper.rs b/components/style/gecko/wrapper.rs
index a3c1ebeec0b..bab4b1e2113 100644
--- a/components/style/gecko/wrapper.rs
+++ b/components/style/gecko/wrapper.rs
@@ -986,7 +986,6 @@ fn get_animation_rule(
     element: &GeckoElement,
     cascade_level: CascadeLevel,
 ) -> Option<Arc<Locked<PropertyDeclarationBlock>>> {
-    use crate::gecko_bindings::sugar::ownership::HasSimpleFFI;
     use crate::properties::longhands::ANIMATABLE_PROPERTY_COUNT;
 
     // There's a very rough correlation between the number of effects
diff --git a/components/style/rule_tree/mod.rs b/components/style/rule_tree/mod.rs
index f165e1f455f..3e2696fff9b 100644
--- a/components/style/rule_tree/mod.rs
+++ b/components/style/rule_tree/mod.rs
@@ -1239,7 +1239,7 @@ impl StrongRuleNode {
         use crate::gecko_bindings::structs::NS_AUTHOR_SPECIFIED_BACKGROUND;
         use crate::gecko_bindings::structs::NS_AUTHOR_SPECIFIED_BORDER;
         use crate::gecko_bindings::structs::NS_AUTHOR_SPECIFIED_PADDING;
-        use crate::properties::{CSSWideKeyword, LonghandId, LonghandIdSet};
+        use crate::properties::{CSSWideKeyword, LonghandId};
         use crate::properties::{PropertyDeclaration, PropertyDeclarationId};
         use crate::values::specified::Color;
         use std::borrow::Cow;
diff --git a/components/style/stylesheet_set.rs b/components/style/stylesheet_set.rs
index 35060a959d6..409978c3a9e 100644
--- a/components/style/stylesheet_set.rs
+++ b/components/style/stylesheet_set.rs
@@ -211,8 +211,6 @@ where
     type Item = (&'a S, SheetRebuildKind);
 
     fn next(&mut self) -> Option<Self::Item> {
-        use std::mem;
-
         loop {
             let potential_sheet = self.iter.next()?;
 
diff --git a/components/style/traversal.rs b/components/style/traversal.rs
index d5a9a5c5033..5ed2388ca5d 100644
--- a/components/style/traversal.rs
+++ b/components/style/traversal.rs
@@ -307,8 +307,6 @@ pub fn resolve_style<E>(
 where
     E: TElement,
 {
-    use crate::style_resolver::StyleResolverForElement;
-
     debug_assert!(
         rule_inclusion == RuleInclusion::DefaultOnly ||
             pseudo.map_or(false, |p| p.is_before_or_after()) ||
@@ -406,7 +404,6 @@ pub fn recalc_style_at<E, D, F>(
     D: DomTraversal<E>,
     F: FnMut(E::ConcreteNode),
 {
-    use crate::traversal_flags::TraversalFlags;
     use std::cmp;
 
     let flags = context.shared.traversal_flags;
diff --git a/components/style/values/generics/font.rs b/components/style/values/generics/font.rs
index cb1ec77e781..36c15172490 100644
--- a/components/style/values/generics/font.rs
+++ b/components/style/values/generics/font.rs
@@ -118,7 +118,7 @@ impl ToCss for FontTag {
     where
         W: Write,
     {
-        use byteorder::{BigEndian, ByteOrder};
+        use byteorder::ByteOrder;
         use std::str;
 
         let mut raw = [0u8; 4];

From a6f32bc762194c1233271b906caaeaabd6f6eb87 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Emilio=20Cobos=20=C3=81lvarez?= <emilio@crisal.io>
Date: Thu, 4 Apr 2019 03:46:55 +0000
Subject: [PATCH 31/59] style: Fix revalidation in <svg:use> subtree.

So as to avoid incorrectly sharing styles across elements.

Differential Revision: https://phabricator.services.mozilla.com/D25918
---
 components/style/dom.rs | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/components/style/dom.rs b/components/style/dom.rs
index 28798e280b6..63f82a3754f 100644
--- a/components/style/dom.rs
+++ b/components/style/dom.rs
@@ -825,11 +825,15 @@ pub trait TElement:
         Self: 'a,
         F: FnMut(&'a CascadeData, QuirksMode, Option<Self>),
     {
+        use rule_collector::containing_shadow_ignoring_svg_use;
+
         let mut doc_rules_apply = !self.each_xbl_cascade_data(|data, quirks_mode| {
             f(data, quirks_mode, None);
         });
 
-        if let Some(shadow) = self.containing_shadow() {
+        // Use the same rules to look for the containing host as we do for rule
+        // collection.
+        if let Some(shadow) = containing_shadow_ignoring_svg_use(*self) {
             doc_rules_apply = false;
             if let Some(data) = shadow.style_data() {
                 f(

From 691eb36ffe53db01629b2d339f51e95776c99723 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Emilio=20Cobos=20=C3=81lvarez?= <emilio@crisal.io>
Date: Thu, 4 Apr 2019 11:34:56 +0000
Subject: [PATCH 32/59] style: Expose colors via cbindgen.

Also s/Foreground/CurrentColor.

Differential Revision: https://phabricator.services.mozilla.com/D25975
---
 .../sugar/style_complex_color.rs              | 14 +++----
 .../properties/longhands/inherited_ui.mako.rs |  1 +
 components/style/values/animated/color.rs     | 24 ++++++------
 components/style/values/computed/color.rs     |  6 +--
 components/style/values/generics/color.rs     | 38 ++++++++++++-------
 components/style/values/specified/color.rs    |  4 +-
 6 files changed, 50 insertions(+), 37 deletions(-)

diff --git a/components/style/gecko_bindings/sugar/style_complex_color.rs b/components/style/gecko_bindings/sugar/style_complex_color.rs
index aec334969d4..de1fad3bbab 100644
--- a/components/style/gecko_bindings/sugar/style_complex_color.rs
+++ b/components/style/gecko_bindings/sugar/style_complex_color.rs
@@ -49,8 +49,8 @@ impl From<ComputedColor> for StyleComplexColor {
     fn from(other: ComputedColor) -> Self {
         match other {
             GenericColor::Numeric(color) => color.into(),
-            GenericColor::Foreground => Self::current_color(),
-            GenericColor::Complex(color, ratios) => {
+            GenericColor::CurrentColor => Self::current_color(),
+            GenericColor::Complex { color, ratios } => {
                 debug_assert!(ratios != ComplexColorRatios::NUMERIC);
                 debug_assert!(ratios != ComplexColorRatios::FOREGROUND);
                 StyleComplexColor {
@@ -73,18 +73,18 @@ impl From<StyleComplexColor> for ComputedColor {
             },
             Tag::eForeground => {
                 debug_assert!(other.mBgRatio == 0. && other.mFgRatio == 1.);
-                GenericColor::Foreground
+                GenericColor::CurrentColor
             },
             Tag::eComplex => {
                 debug_assert!(other.mBgRatio != 1. || other.mFgRatio != 0.);
                 debug_assert!(other.mBgRatio != 0. || other.mFgRatio != 1.);
-                GenericColor::Complex(
-                    convert_nscolor_to_rgba(other.mColor),
-                    ComplexColorRatios {
+                GenericColor::Complex {
+                    color: convert_nscolor_to_rgba(other.mColor),
+                    ratios: ComplexColorRatios {
                         bg: other.mBgRatio,
                         fg: other.mFgRatio,
                     },
-                )
+                }
             },
             Tag::eAuto => unreachable!("Unsupport StyleComplexColor with tag eAuto"),
         }
diff --git a/components/style/properties/longhands/inherited_ui.mako.rs b/components/style/properties/longhands/inherited_ui.mako.rs
index 94709e1a681..07264372995 100644
--- a/components/style/properties/longhands/inherited_ui.mako.rs
+++ b/components/style/properties/longhands/inherited_ui.mako.rs
@@ -63,6 +63,7 @@ ${helpers.predefined_type(
     "generics::color::ColorOrAuto::Auto",
     spec="https://drafts.csswg.org/css-ui/#caret-color",
     animation_value_type="AnimatedCaretColor",
+    boxed=True,
     ignored_when_colors_disabled=True,
     products="gecko",
 )}
diff --git a/components/style/values/animated/color.rs b/components/style/values/animated/color.rs
index c8d5213b49b..14b1d0c539c 100644
--- a/components/style/values/animated/color.rs
+++ b/components/style/values/animated/color.rs
@@ -100,8 +100,8 @@ impl Color {
     fn effective_intermediate_rgba(&self) -> RGBA {
         match *self {
             GenericColor::Numeric(color) => color,
-            GenericColor::Foreground => RGBA::transparent(),
-            GenericColor::Complex(color, ratios) => RGBA {
+            GenericColor::CurrentColor => RGBA::transparent(),
+            GenericColor::Complex { color, ratios } => RGBA {
                 alpha: color.alpha * ratios.bg,
                 ..color.clone()
             },
@@ -111,8 +111,8 @@ impl Color {
     fn effective_ratios(&self) -> ComplexColorRatios {
         match *self {
             GenericColor::Numeric(..) => ComplexColorRatios::NUMERIC,
-            GenericColor::Foreground => ComplexColorRatios::FOREGROUND,
-            GenericColor::Complex(.., ratios) => ratios,
+            GenericColor::CurrentColor => ComplexColorRatios::CURRENT_COLOR,
+            GenericColor::Complex { ratios, .. } => ratios,
         }
     }
 }
@@ -128,18 +128,18 @@ impl Animate for Color {
 
         Ok(match (*self, *other, procedure) {
             // Any interpolation of currentcolor with currentcolor returns currentcolor.
-            (Foreground, Foreground, Procedure::Interpolate { .. }) => Foreground,
+            (CurrentColor, CurrentColor, Procedure::Interpolate { .. }) => CurrentColor,
             // Animating two numeric colors.
             (Numeric(c1), Numeric(c2), _) => Numeric(c1.animate(&c2, procedure)?),
             // Combinations of numeric color and currentcolor
-            (Foreground, Numeric(color), _) => Self::with_ratios(
+            (CurrentColor, Numeric(color), _) => Self::with_ratios(
                 color,
                 ComplexColorRatios {
                     bg: other_weight as f32,
                     fg: this_weight as f32,
                 },
             ),
-            (Numeric(color), Foreground, _) => Self::with_ratios(
+            (Numeric(color), CurrentColor, _) => Self::with_ratios(
                 color,
                 ComplexColorRatios {
                     bg: this_weight as f32,
@@ -148,7 +148,7 @@ impl Animate for Color {
             ),
 
             // Any other animation of currentcolor with currentcolor.
-            (Foreground, Foreground, _) => Self::with_ratios(
+            (CurrentColor, CurrentColor, _) => Self::with_ratios(
                 RGBA::transparent(),
                 ComplexColorRatios {
                     bg: 0.,
@@ -162,8 +162,8 @@ impl Animate for Color {
                 fn scaled_rgba(color: &Color) -> RGBA {
                     match *color {
                         GenericColor::Numeric(color) => color,
-                        GenericColor::Foreground => RGBA::transparent(),
-                        GenericColor::Complex(color, ratios) => RGBA {
+                        GenericColor::CurrentColor => RGBA::transparent(),
+                        GenericColor::Complex { color, ratios } => RGBA {
                             red: color.red * ratios.bg,
                             green: color.green * ratios.bg,
                             blue: color.blue * ratios.bg,
@@ -236,9 +236,9 @@ impl ComputeSquaredDistance for Color {
 
         // All comments from the Animate impl also applies here.
         Ok(match (*self, *other) {
-            (Foreground, Foreground) => SquaredDistance::from_sqrt(0.),
+            (CurrentColor, CurrentColor) => SquaredDistance::from_sqrt(0.),
             (Numeric(c1), Numeric(c2)) => c1.compute_squared_distance(&c2)?,
-            (Foreground, Numeric(color)) | (Numeric(color), Foreground) => {
+            (CurrentColor, Numeric(color)) | (Numeric(color), CurrentColor) => {
                 // `computed_squared_distance` is symmetric.
                 color.compute_squared_distance(&RGBA::transparent())? +
                     SquaredDistance::from_sqrt(1.)
diff --git a/components/style/values/computed/color.rs b/components/style/values/computed/color.rs
index 6795b399888..ade384a99ad 100644
--- a/components/style/values/computed/color.rs
+++ b/components/style/values/computed/color.rs
@@ -33,8 +33,8 @@ impl Color {
             // Common cases that the complex color is either pure numeric
             // color or pure currentcolor.
             GenericColor::Numeric(color) => return color,
-            GenericColor::Foreground => return fg_color,
-            GenericColor::Complex(color, ratios) => (color, ratios),
+            GenericColor::CurrentColor => return fg_color,
+            GenericColor::Complex { color, ratios } => (color, ratios),
         };
 
         // For the more complicated case that the alpha value differs,
@@ -76,7 +76,7 @@ impl ToCss for Color {
     {
         match *self {
             GenericColor::Numeric(color) => color.to_css(dest),
-            GenericColor::Foreground => CSSParserColor::CurrentColor.to_css(dest),
+            GenericColor::CurrentColor => CSSParserColor::CurrentColor.to_css(dest),
             _ => Ok(()),
         }
     }
diff --git a/components/style/values/generics/color.rs b/components/style/values/generics/color.rs
index 34b8f0608f8..5aa287baadf 100644
--- a/components/style/values/generics/color.rs
+++ b/components/style/values/generics/color.rs
@@ -7,44 +7,53 @@
 /// Ratios representing the contribution of color and currentcolor to
 /// the final color value.
 #[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, ToAnimatedValue, ToShmem)]
+#[repr(C)]
 pub struct ComplexColorRatios {
     /// Numeric color contribution.
     pub bg: f32,
-    /// Foreground color, aka currentcolor, contribution.
+    /// currentcolor contribution.
     pub fg: f32,
 }
 
 impl ComplexColorRatios {
     /// Ratios representing a `Numeric` color.
     pub const NUMERIC: ComplexColorRatios = ComplexColorRatios { bg: 1., fg: 0. };
-    /// Ratios representing the `Foreground` color.
-    pub const FOREGROUND: ComplexColorRatios = ComplexColorRatios { bg: 0., fg: 1. };
+    /// Ratios representing the `CurrentColor` color.
+    pub const CURRENT_COLOR: ComplexColorRatios = ComplexColorRatios { bg: 0., fg: 1. };
 }
 
 /// This enum represents a combined color from a numeric color and
 /// the current foreground color (currentcolor keyword).
 #[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, ToAnimatedValue, ToShmem)]
-pub enum Color<RGBA> {
+#[repr(C, u8)]
+pub enum GenericColor<RGBA> {
     ///  Numeric RGBA color.
     Numeric(RGBA),
 
     /// The current foreground color.
-    Foreground,
+    CurrentColor,
 
     /// A linear combination of numeric color and currentcolor.
     /// The formula is: `color * ratios.bg + currentcolor * ratios.fg`.
-    Complex(RGBA, ComplexColorRatios),
+    Complex {
+        /// The actual numeric color.
+        color: RGBA,
+        /// The ratios of mixing between numeric and currentcolor.
+        ratios: ComplexColorRatios,
+    }
 }
 
+pub use self::GenericColor as Color;
+
 impl<RGBA> Color<RGBA> {
     /// Create a color based upon the specified ratios.
     pub fn with_ratios(color: RGBA, ratios: ComplexColorRatios) -> Self {
         if ratios == ComplexColorRatios::NUMERIC {
             Color::Numeric(color)
-        } else if ratios == ComplexColorRatios::FOREGROUND {
-            Color::Foreground
+        } else if ratios == ComplexColorRatios::CURRENT_COLOR {
+            Color::CurrentColor
         } else {
-            Color::Complex(color, ratios)
+            Color::Complex { color, ratios }
         }
     }
 
@@ -55,7 +64,7 @@ impl<RGBA> Color<RGBA> {
 
     /// Returns a complex color value representing currentcolor.
     pub fn currentcolor() -> Self {
-        Color::Foreground
+        Color::CurrentColor
     }
 
     /// Whether it is a numeric color (no currentcolor component).
@@ -65,7 +74,7 @@ impl<RGBA> Color<RGBA> {
 
     /// Whether it is a currentcolor value (no numeric color component).
     pub fn is_currentcolor(&self) -> bool {
-        matches!(*self, Color::Foreground)
+        matches!(*self, Color::CurrentColor)
     }
 }
 
@@ -92,9 +101,12 @@ impl<RGBA> From<RGBA> for Color<RGBA> {
     ToCss,
     ToShmem,
 )]
-pub enum ColorOrAuto<C> {
-    /// A `<color>
+#[repr(C, u8)]
+pub enum GenericColorOrAuto<C> {
+    /// A `<color>`.
     Color(C),
     /// `auto`
     Auto,
 }
+
+pub use self::GenericColorOrAuto as ColorOrAuto;
diff --git a/components/style/values/specified/color.rs b/components/style/values/specified/color.rs
index 526ed260dbd..00a2033ef2a 100644
--- a/components/style/values/specified/color.rs
+++ b/components/style/values/specified/color.rs
@@ -387,8 +387,8 @@ impl ToComputedValue for Color {
     fn from_computed_value(computed: &ComputedColor) -> Self {
         match *computed {
             GenericColor::Numeric(color) => Color::rgba(color),
-            GenericColor::Foreground => Color::currentcolor(),
-            GenericColor::Complex(..) => Color::Complex(*computed),
+            GenericColor::CurrentColor => Color::currentcolor(),
+            GenericColor::Complex { .. } => Color::Complex(*computed),
         }
     }
 }

From 53ccbc57515e494438472f9f3cae61e4895d7b4f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Emilio=20Cobos=20=C3=81lvarez?= <emilio@crisal.io>
Date: Thu, 4 Apr 2019 11:35:16 +0000
Subject: [PATCH 33/59] style: Use the rust color representation.

Differential Revision: https://phabricator.services.mozilla.com/D25976
---
 components/style/gecko_bindings/sugar/mod.rs  |   1 -
 .../sugar/style_complex_color.rs              | 111 ------------------
 components/style/properties/gecko.mako.rs     |  99 +---------------
 components/style/values/computed/ui.rs        |   2 +-
 components/style/values/generics/ui.rs        |   5 +-
 5 files changed, 9 insertions(+), 209 deletions(-)
 delete mode 100644 components/style/gecko_bindings/sugar/style_complex_color.rs

diff --git a/components/style/gecko_bindings/sugar/mod.rs b/components/style/gecko_bindings/sugar/mod.rs
index 642b5ad203a..de981bd289a 100644
--- a/components/style/gecko_bindings/sugar/mod.rs
+++ b/components/style/gecko_bindings/sugar/mod.rs
@@ -15,4 +15,3 @@ mod ns_t_array;
 pub mod origin_flags;
 pub mod ownership;
 pub mod refptr;
-mod style_complex_color;
diff --git a/components/style/gecko_bindings/sugar/style_complex_color.rs b/components/style/gecko_bindings/sugar/style_complex_color.rs
deleted file mode 100644
index de1fad3bbab..00000000000
--- a/components/style/gecko_bindings/sugar/style_complex_color.rs
+++ /dev/null
@@ -1,111 +0,0 @@
-/* This Source Code Form is subject to the terms of the Mozilla Public
- * License, v. 2.0. If a copy of the MPL was not distributed with this
- * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
-
-//! Rust helpers to interact with Gecko's StyleComplexColor.
-
-use crate::gecko::values::{convert_nscolor_to_rgba, convert_rgba_to_nscolor};
-use crate::gecko_bindings::structs::StyleComplexColor;
-use crate::gecko_bindings::structs::StyleComplexColor_Tag as Tag;
-use crate::values::computed::{Color as ComputedColor, ColorOrAuto, RGBAColor as ComputedRGBA};
-use crate::values::generics::color::{
-    Color as GenericColor, ColorOrAuto as GenericColorOrAuto, ComplexColorRatios,
-};
-
-impl StyleComplexColor {
-    /// Create a `StyleComplexColor` value that represents `currentColor`.
-    pub fn current_color() -> Self {
-        StyleComplexColor {
-            mColor: 0,
-            mBgRatio: 0.,
-            mFgRatio: 1.,
-            mTag: Tag::eForeground,
-        }
-    }
-
-    /// Create a `StyleComplexColor` value that represents `auto`.
-    pub fn auto() -> Self {
-        StyleComplexColor {
-            mColor: 0,
-            mBgRatio: 0.,
-            mFgRatio: 1.,
-            mTag: Tag::eAuto,
-        }
-    }
-}
-
-impl From<ComputedRGBA> for StyleComplexColor {
-    fn from(other: ComputedRGBA) -> Self {
-        StyleComplexColor {
-            mColor: convert_rgba_to_nscolor(&other),
-            mBgRatio: 1.,
-            mFgRatio: 0.,
-            mTag: Tag::eNumeric,
-        }
-    }
-}
-
-impl From<ComputedColor> for StyleComplexColor {
-    fn from(other: ComputedColor) -> Self {
-        match other {
-            GenericColor::Numeric(color) => color.into(),
-            GenericColor::CurrentColor => Self::current_color(),
-            GenericColor::Complex { color, ratios } => {
-                debug_assert!(ratios != ComplexColorRatios::NUMERIC);
-                debug_assert!(ratios != ComplexColorRatios::FOREGROUND);
-                StyleComplexColor {
-                    mColor: convert_rgba_to_nscolor(&color).into(),
-                    mBgRatio: ratios.bg,
-                    mFgRatio: ratios.fg,
-                    mTag: Tag::eComplex,
-                }
-            },
-        }
-    }
-}
-
-impl From<StyleComplexColor> for ComputedColor {
-    fn from(other: StyleComplexColor) -> Self {
-        match other.mTag {
-            Tag::eNumeric => {
-                debug_assert!(other.mBgRatio == 1. && other.mFgRatio == 0.);
-                GenericColor::Numeric(convert_nscolor_to_rgba(other.mColor))
-            },
-            Tag::eForeground => {
-                debug_assert!(other.mBgRatio == 0. && other.mFgRatio == 1.);
-                GenericColor::CurrentColor
-            },
-            Tag::eComplex => {
-                debug_assert!(other.mBgRatio != 1. || other.mFgRatio != 0.);
-                debug_assert!(other.mBgRatio != 0. || other.mFgRatio != 1.);
-                GenericColor::Complex {
-                    color: convert_nscolor_to_rgba(other.mColor),
-                    ratios: ComplexColorRatios {
-                        bg: other.mBgRatio,
-                        fg: other.mFgRatio,
-                    },
-                }
-            },
-            Tag::eAuto => unreachable!("Unsupport StyleComplexColor with tag eAuto"),
-        }
-    }
-}
-
-impl From<ColorOrAuto> for StyleComplexColor {
-    fn from(other: ColorOrAuto) -> Self {
-        match other {
-            GenericColorOrAuto::Color(color) => color.into(),
-            GenericColorOrAuto::Auto => StyleComplexColor::auto(),
-        }
-    }
-}
-
-impl From<StyleComplexColor> for ColorOrAuto {
-    fn from(other: StyleComplexColor) -> Self {
-        if other.mTag != Tag::eAuto {
-            GenericColorOrAuto::Color(other.into())
-        } else {
-            GenericColorOrAuto::Auto
-        }
-    }
-}
diff --git a/components/style/properties/gecko.mako.rs b/components/style/properties/gecko.mako.rs
index 3bb8264bf09..0eaab919110 100644
--- a/components/style/properties/gecko.mako.rs
+++ b/components/style/properties/gecko.mako.rs
@@ -397,34 +397,6 @@ def set_gecko_property(ffi_name, expr):
     }
 </%def>
 
-<%def name="impl_color_setter(ident, gecko_ffi_name)">
-    #[allow(unreachable_code)]
-    #[allow(non_snake_case)]
-    pub fn set_${ident}(&mut self, v: longhands::${ident}::computed_value::T) {
-        ${set_gecko_property(gecko_ffi_name, "v.into()")}
-    }
-</%def>
-
-<%def name="impl_color_copy(ident, gecko_ffi_name)">
-    #[allow(non_snake_case)]
-    pub fn copy_${ident}_from(&mut self, other: &Self) {
-        let color = ${get_gecko_property(gecko_ffi_name, self_param = "other")};
-        ${set_gecko_property(gecko_ffi_name, "color")};
-    }
-
-    #[allow(non_snake_case)]
-    pub fn reset_${ident}(&mut self, other: &Self) {
-        self.copy_${ident}_from(other)
-    }
-</%def>
-
-<%def name="impl_color_clone(ident, gecko_ffi_name)">
-    #[allow(non_snake_case)]
-    pub fn clone_${ident}(&self) -> longhands::${ident}::computed_value::T {
-        ${get_gecko_property(gecko_ffi_name)}.into()
-    }
-</%def>
-
 <%def name="impl_keyword(ident, gecko_ffi_name, keyword, cast_type='u8', **kwargs)">
 <%call expr="impl_keyword_setter(ident, gecko_ffi_name, keyword, cast_type, **kwargs)"></%call>
 <%call expr="impl_simple_copy(ident, gecko_ffi_name, **kwargs)"></%call>
@@ -449,12 +421,6 @@ def set_gecko_property(ffi_name, expr):
     }
 </%def>
 
-<%def name="impl_color(ident, gecko_ffi_name)">
-<%call expr="impl_color_setter(ident, gecko_ffi_name)"></%call>
-<%call expr="impl_color_copy(ident, gecko_ffi_name)"></%call>
-<%call expr="impl_color_clone(ident, gecko_ffi_name)"></%call>
-</%def>
-
 <%def name="impl_rgba_color(ident, gecko_ffi_name)">
     #[allow(non_snake_case)]
     pub fn set_${ident}(&mut self, v: longhands::${ident}::computed_value::T) {
@@ -1238,8 +1204,6 @@ impl Clone for ${style_struct.gecko_struct_name} {
 
     # Types used with predefined_type()-defined properties that we can auto-generate.
     predefined_types = {
-        "Color": impl_color,
-        "ColorOrAuto": impl_color,
         "length::LengthOrAuto": impl_style_coord,
         "length::LengthOrNormal": impl_style_coord,
         "length::NonNegativeLengthOrAuto": impl_style_coord,
@@ -1247,7 +1211,6 @@ impl Clone for ${style_struct.gecko_struct_name} {
         "Length": impl_absolute_length,
         "LengthOrNormal": impl_style_coord,
         "LengthPercentageOrAuto": impl_style_coord,
-        "MozListReversed": impl_simple,
         "MozScriptMinSize": impl_absolute_length,
         "RGBAColor": impl_rgba_color,
         "SVGLength": impl_svg_length,
@@ -1379,7 +1342,7 @@ fn static_assert() {
         self.gecko.mBorderStyle[${side.index}]
     }
 
-    <% impl_color("border_%s_color" % side.ident, "mBorder%sColor" % side.name) %>
+    <% impl_simple("border_%s_color" % side.ident, "mBorder%sColor" % side.name) %>
 
     <% impl_non_negative_length("border_%s_width" % side.ident,
                                 "mComputedBorder.%s" % side.ident,
@@ -4386,23 +4349,11 @@ clip-path
     }
 </%self:impl_trait>
 
-<%self:impl_trait style_struct_name="Color"
-                  skip_longhands="*">
-    pub fn set_color(&mut self, v: longhands::color::computed_value::T) {
-        let result = convert_rgba_to_nscolor(&v);
-        ${set_gecko_property("mColor", "result")}
-    }
-
-    <%call expr="impl_simple_copy('color', 'mColor')"></%call>
-
-    pub fn clone_color(&self) -> longhands::color::computed_value::T {
-        let color = ${get_gecko_property("mColor")} as u32;
-        convert_nscolor_to_rgba(color)
-    }
+<%self:impl_trait style_struct_name="Color" skip_longhands="color">
+    ${impl_rgba_color("color", "mColor")}
 </%self:impl_trait>
 
-<%self:impl_trait style_struct_name="InheritedUI"
-                  skip_longhands="cursor scrollbar-color">
+<%self:impl_trait style_struct_name="InheritedUI" skip_longhands="cursor">
     pub fn set_cursor(&mut self, v: longhands::cursor::computed_value::T) {
         self.gecko.mCursor = v.keyword;
         unsafe {
@@ -4464,48 +4415,6 @@ clip-path
 
         longhands::cursor::computed_value::T { images, keyword }
     }
-
-    pub fn set_scrollbar_color(&mut self, v: longhands::scrollbar_color::computed_value::T) {
-        use crate::gecko_bindings::structs::StyleComplexColor;
-        use crate::values::generics::ui::ScrollbarColor;
-        match v {
-            ScrollbarColor::Auto => {
-                self.gecko.mScrollbarFaceColor = StyleComplexColor::auto();
-                self.gecko.mScrollbarTrackColor = StyleComplexColor::auto();
-            }
-            ScrollbarColor::Colors { thumb, track } => {
-                self.gecko.mScrollbarFaceColor = thumb.into();
-                self.gecko.mScrollbarTrackColor = track.into();
-            }
-        }
-    }
-
-    pub fn copy_scrollbar_color_from(&mut self, other: &Self) {
-        self.gecko.mScrollbarFaceColor = other.gecko.mScrollbarFaceColor;
-        self.gecko.mScrollbarTrackColor = other.gecko.mScrollbarTrackColor;
-    }
-
-    pub fn reset_scrollbar_color(&mut self, other: &Self) {
-        self.copy_scrollbar_color_from(other);
-    }
-
-    pub fn clone_scrollbar_color(&self) -> longhands::scrollbar_color::computed_value::T {
-        use crate::gecko_bindings::structs::StyleComplexColor_Tag as Tag;
-        use crate::values::generics::ui::ScrollbarColor;
-        debug_assert!(
-            (self.gecko.mScrollbarFaceColor.mTag == Tag::eAuto) ==
-            (self.gecko.mScrollbarTrackColor.mTag == Tag::eAuto),
-            "Whether the two colors are `auto` should match",
-        );
-        if self.gecko.mScrollbarFaceColor.mTag == Tag::eAuto {
-            ScrollbarColor::Auto
-        } else {
-            ScrollbarColor::Colors {
-                thumb: self.gecko.mScrollbarFaceColor.into(),
-                track: self.gecko.mScrollbarTrackColor.into(),
-            }
-        }
-    }
 </%self:impl_trait>
 
 <%self:impl_trait style_struct_name="Column"
diff --git a/components/style/values/computed/ui.rs b/components/style/values/computed/ui.rs
index 0c37ea4f518..21914995951 100644
--- a/components/style/values/computed/ui.rs
+++ b/components/style/values/computed/ui.rs
@@ -19,4 +19,4 @@ pub type Cursor = generics::Cursor<CursorImage>;
 pub type CursorImage = generics::CursorImage<ComputedImageUrl, Number>;
 
 /// A computed value for `scrollbar-color` property.
-pub type ScrollbarColor = generics::ScrollbarColor<Color>;
+pub type ScrollbarColor = generics::GenericScrollbarColor<Color>;
diff --git a/components/style/values/generics/ui.rs b/components/style/values/generics/ui.rs
index e6eed9afaa5..294a29d04af 100644
--- a/components/style/values/generics/ui.rs
+++ b/components/style/values/generics/ui.rs
@@ -86,7 +86,8 @@ impl<ImageUrl: ToCss, Number: ToCss> ToCss for CursorImage<ImageUrl, Number> {
     ToCss,
     ToShmem,
 )]
-pub enum ScrollbarColor<Color> {
+#[repr(C, u8)]
+pub enum GenericScrollbarColor<Color> {
     /// `auto`
     Auto,
     /// `<color>{2}`
@@ -98,6 +99,8 @@ pub enum ScrollbarColor<Color> {
     },
 }
 
+pub use self::GenericScrollbarColor as ScrollbarColor;
+
 impl<Color> Default for ScrollbarColor<Color> {
     #[inline]
     fn default() -> Self {

From 79fc59c75f76de0b0b26a492e93418e0b3ed4823 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Emilio=20Cobos=20=C3=81lvarez?= <emilio@crisal.io>
Date: Thu, 4 Apr 2019 11:35:33 +0000
Subject: [PATCH 34/59] style: Use only the new name for StyleColor.

That is, change all uses of StyleComplexColor to just StyleColor.

Differential Revision: https://phabricator.services.mozilla.com/D25977
---
 components/style/properties/properties.mako.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/components/style/properties/properties.mako.rs b/components/style/properties/properties.mako.rs
index db9fb9fbd3b..5390c8e8270 100644
--- a/components/style/properties/properties.mako.rs
+++ b/components/style/properties/properties.mako.rs
@@ -1293,7 +1293,7 @@ impl LonghandId {
     ///
     /// In Gecko, there are some properties still that compute currentcolor
     /// down to an RGBA color at computed value time, instead of as
-    /// `StyleComplexColor`s. For these properties, we must return `false`,
+    /// `StyleColor`s. For these properties, we must return `false`,
     /// so that we correctly avoid caching style data in the rule tree.
     pub fn stores_complex_colors_lossily(&self) -> bool {
         % if product == "gecko":

From ef0b6bb22570f9ae51bac92a7b65e4cfc8885b15 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Emilio=20Cobos=20=C3=81lvarez?= <emilio@crisal.io>
Date: Thu, 4 Apr 2019 17:39:15 +0000
Subject: [PATCH 35/59] style: Trivially remove some dead code.

Differential Revision: https://phabricator.services.mozilla.com/D26154
---
 components/style/properties/gecko.mako.rs   | 4 ----
 components/style/values/computed/length.rs  | 6 ------
 components/style/values/specified/length.rs | 6 ------
 3 files changed, 16 deletions(-)

diff --git a/components/style/properties/gecko.mako.rs b/components/style/properties/gecko.mako.rs
index 0eaab919110..2e2a55a16bb 100644
--- a/components/style/properties/gecko.mako.rs
+++ b/components/style/properties/gecko.mako.rs
@@ -1204,13 +1204,9 @@ impl Clone for ${style_struct.gecko_struct_name} {
 
     # Types used with predefined_type()-defined properties that we can auto-generate.
     predefined_types = {
-        "length::LengthOrAuto": impl_style_coord,
-        "length::LengthOrNormal": impl_style_coord,
         "length::NonNegativeLengthOrAuto": impl_style_coord,
         "length::NonNegativeLengthPercentageOrNormal": impl_style_coord,
         "Length": impl_absolute_length,
-        "LengthOrNormal": impl_style_coord,
-        "LengthPercentageOrAuto": impl_style_coord,
         "MozScriptMinSize": impl_absolute_length,
         "RGBAColor": impl_rgba_color,
         "SVGLength": impl_svg_length,
diff --git a/components/style/values/computed/length.rs b/components/style/values/computed/length.rs
index 0587dc46791..0fd624b5c55 100644
--- a/components/style/values/computed/length.rs
+++ b/components/style/values/computed/length.rs
@@ -710,9 +710,6 @@ pub type NonNegativeLengthOrAuto = generics::GenericLengthPercentageOrAuto<NonNe
 /// Either a computed `<length>` or a `<number>` value.
 pub type LengthOrNumber = GenericLengthOrNumber<Length, Number>;
 
-/// Either a computed `<length>` or the `normal` keyword.
-pub type LengthOrNormal = Either<Length, Normal>;
-
 /// A wrapper of Length, whose value must be >= 0.
 pub type NonNegativeLength = NonNegative<Length>;
 
@@ -783,9 +780,6 @@ impl From<NonNegativeLength> for Au {
     }
 }
 
-/// Either a computed NonNegativeLength or the `normal` keyword.
-pub type NonNegativeLengthOrNormal = Either<NonNegativeLength, Normal>;
-
 /// Either a computed NonNegativeLengthPercentage or the `normal` keyword.
 pub type NonNegativeLengthPercentageOrNormal = Either<NonNegativeLengthPercentage, Normal>;
 
diff --git a/components/style/values/specified/length.rs b/components/style/values/specified/length.rs
index fcbae0aa2d6..8d29fe53a00 100644
--- a/components/style/values/specified/length.rs
+++ b/components/style/values/specified/length.rs
@@ -956,9 +956,6 @@ impl NonNegativeLengthPercentageOrAuto {
 /// A wrapper of LengthPercentage, whose value must be >= 0.
 pub type NonNegativeLengthPercentage = NonNegative<LengthPercentage>;
 
-/// Either a computed NonNegativeLength or the `normal` keyword.
-pub type NonNegativeLengthOrNormal = Either<NonNegativeLength, Normal>;
-
 /// Either a NonNegativeLengthPercentage or the `normal` keyword.
 pub type NonNegativeLengthPercentageOrNormal = Either<NonNegativeLengthPercentage, Normal>;
 
@@ -998,9 +995,6 @@ impl NonNegativeLengthPercentage {
     }
 }
 
-/// Either a `<length>` or the `normal` keyword.
-pub type LengthOrNormal = Either<Length, Normal>;
-
 /// Either a `<length>` or the `auto` keyword.
 ///
 /// Note that we use LengthPercentage just for convenience, since it pretty much

From f8fce03e82e196ae029f7b054c56b78866c79a6c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Emilio=20Cobos=20=C3=81lvarez?= <emilio@crisal.io>
Date: Thu, 4 Apr 2019 18:29:57 +0000
Subject: [PATCH 36/59] style: Use Servo lengths for column-width.

Differential Revision: https://phabricator.services.mozilla.com/D26155
---
 components/style/properties/gecko.mako.rs | 1 -
 1 file changed, 1 deletion(-)

diff --git a/components/style/properties/gecko.mako.rs b/components/style/properties/gecko.mako.rs
index 2e2a55a16bb..3c4a45666b1 100644
--- a/components/style/properties/gecko.mako.rs
+++ b/components/style/properties/gecko.mako.rs
@@ -1204,7 +1204,6 @@ impl Clone for ${style_struct.gecko_struct_name} {
 
     # Types used with predefined_type()-defined properties that we can auto-generate.
     predefined_types = {
-        "length::NonNegativeLengthOrAuto": impl_style_coord,
         "length::NonNegativeLengthPercentageOrNormal": impl_style_coord,
         "Length": impl_absolute_length,
         "MozScriptMinSize": impl_absolute_length,

From 681f861018159c8d94df7f406a75d09770a1de2d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Emilio=20Cobos=20=C3=81lvarez?= <emilio@crisal.io>
Date: Thu, 4 Apr 2019 18:32:09 +0000
Subject: [PATCH 37/59] style: Use rust lengths for outline-offset.

Differential Revision: https://phabricator.services.mozilla.com/D26156
---
 components/style/properties/gecko.mako.rs | 1 -
 1 file changed, 1 deletion(-)

diff --git a/components/style/properties/gecko.mako.rs b/components/style/properties/gecko.mako.rs
index 3c4a45666b1..44b76f28b5a 100644
--- a/components/style/properties/gecko.mako.rs
+++ b/components/style/properties/gecko.mako.rs
@@ -1205,7 +1205,6 @@ impl Clone for ${style_struct.gecko_struct_name} {
     # Types used with predefined_type()-defined properties that we can auto-generate.
     predefined_types = {
         "length::NonNegativeLengthPercentageOrNormal": impl_style_coord,
-        "Length": impl_absolute_length,
         "MozScriptMinSize": impl_absolute_length,
         "RGBAColor": impl_rgba_color,
         "SVGLength": impl_svg_length,

From 5d2724994cd25b717618b6ea792ee51ea12a6da4 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Emilio=20Cobos=20=C3=81lvarez?= <emilio@crisal.io>
Date: Sat, 6 Apr 2019 17:47:58 +0000
Subject: [PATCH 38/59] style: Remove the last usage of lossy currentcolor.

We don't have lossy currentcolor in the style system anymore, except for a
single property -moz-font-smoothing-background-color.

I could've converted it into a proper StyleColor and thread down all the
necessary information to the font metrics code.

But it doesn't really seem worth it given it's not exposed to the web, so I just
did the simplest thing, which is making currentcolor compute to transparent to
that specific property.

This patch also removes the stores_complex_colors_lossily code and related,
since now we always can cache computed colors.

Differential Revision: https://phabricator.services.mozilla.com/D26187
---
 components/style/properties/gecko.mako.rs     | 18 +--------
 .../properties/longhands/background.mako.rs   |  2 +-
 .../style/properties/longhands/font.mako.rs   |  6 +--
 .../style/properties/properties.mako.rs       | 26 -------------
 components/style/values/computed/color.rs     |  8 ++--
 components/style/values/computed/mod.rs       |  2 +-
 components/style/values/specified/color.rs    | 38 +++++++------------
 components/style/values/specified/mod.rs      |  2 +-
 8 files changed, 24 insertions(+), 78 deletions(-)

diff --git a/components/style/properties/gecko.mako.rs b/components/style/properties/gecko.mako.rs
index 44b76f28b5a..837a295fb60 100644
--- a/components/style/properties/gecko.mako.rs
+++ b/components/style/properties/gecko.mako.rs
@@ -40,8 +40,6 @@ use crate::gecko_bindings::structs::nsCSSPropertyID;
 use crate::gecko_bindings::structs::mozilla::PseudoStyleType;
 use crate::gecko_bindings::sugar::ns_style_coord::{CoordDataValue, CoordData, CoordDataMut};
 use crate::gecko_bindings::sugar::refptr::RefPtr;
-use crate::gecko::values::convert_nscolor_to_rgba;
-use crate::gecko::values::convert_rgba_to_nscolor;
 use crate::gecko::values::GeckoStyleCoordConvertible;
 use crate::gecko::values::round_border_to_device_pixels;
 use crate::logical_geometry::WritingMode;
@@ -421,18 +419,6 @@ def set_gecko_property(ffi_name, expr):
     }
 </%def>
 
-<%def name="impl_rgba_color(ident, gecko_ffi_name)">
-    #[allow(non_snake_case)]
-    pub fn set_${ident}(&mut self, v: longhands::${ident}::computed_value::T) {
-        ${set_gecko_property(gecko_ffi_name, "convert_rgba_to_nscolor(&v)")}
-    }
-    <%call expr="impl_simple_copy(ident, gecko_ffi_name)"></%call>
-    #[allow(non_snake_case)]
-    pub fn clone_${ident}(&self) -> longhands::${ident}::computed_value::T {
-        convert_nscolor_to_rgba(${get_gecko_property(gecko_ffi_name)})
-    }
-</%def>
-
 <%def name="impl_svg_length(ident, gecko_ffi_name)">
     // When context-value is used on an SVG length, the corresponding flag is
     // set on mContextFlags, and the length field is set to the initial value.
@@ -1206,7 +1192,6 @@ impl Clone for ${style_struct.gecko_struct_name} {
     predefined_types = {
         "length::NonNegativeLengthPercentageOrNormal": impl_style_coord,
         "MozScriptMinSize": impl_absolute_length,
-        "RGBAColor": impl_rgba_color,
         "SVGLength": impl_svg_length,
         "SVGOpacity": impl_svg_opacity,
         "SVGPaint": impl_svg_paint,
@@ -4343,8 +4328,7 @@ clip-path
     }
 </%self:impl_trait>
 
-<%self:impl_trait style_struct_name="Color" skip_longhands="color">
-    ${impl_rgba_color("color", "mColor")}
+<%self:impl_trait style_struct_name="Color">
 </%self:impl_trait>
 
 <%self:impl_trait style_struct_name="InheritedUI" skip_longhands="cursor">
diff --git a/components/style/properties/longhands/background.mako.rs b/components/style/properties/longhands/background.mako.rs
index c6a25be53c1..42344a18cb9 100644
--- a/components/style/properties/longhands/background.mako.rs
+++ b/components/style/properties/longhands/background.mako.rs
@@ -9,7 +9,7 @@
 ${helpers.predefined_type(
     "background-color",
     "Color",
-    "computed_value::T::transparent()",
+    "computed::Color::transparent()",
     initial_specified_value="SpecifiedValue::transparent()",
     spec="https://drafts.csswg.org/css-backgrounds/#background-color",
     animation_value_type="AnimatedColor",
diff --git a/components/style/properties/longhands/font.mako.rs b/components/style/properties/longhands/font.mako.rs
index b253fde0b8d..7f7b66c3572 100644
--- a/components/style/properties/longhands/font.mako.rs
+++ b/components/style/properties/longhands/font.mako.rs
@@ -521,9 +521,9 @@ ${helpers.single_keyword(
 
 ${helpers.predefined_type(
     "-moz-font-smoothing-background-color",
-    "RGBAColor",
-    "RGBA::transparent()",
-    animation_value_type="AnimatedRGBA",
+    "color::MozFontSmoothingBackgroundColor",
+    "computed::color::MozFontSmoothingBackgroundColor::transparent()",
+    animation_value_type="none",
     products="gecko",
     gecko_ffi_name="mFont.fontSmoothingBackgroundColor",
     enabled_in="chrome",
diff --git a/components/style/properties/properties.mako.rs b/components/style/properties/properties.mako.rs
index 5390c8e8270..99a91179150 100644
--- a/components/style/properties/properties.mako.rs
+++ b/components/style/properties/properties.mako.rs
@@ -1287,32 +1287,6 @@ impl LonghandId {
             LonghandId::Direction
         )
     }
-
-    /// Whether computed values of this property lossily convert any complex
-    /// colors into RGBA colors.
-    ///
-    /// In Gecko, there are some properties still that compute currentcolor
-    /// down to an RGBA color at computed value time, instead of as
-    /// `StyleColor`s. For these properties, we must return `false`,
-    /// so that we correctly avoid caching style data in the rule tree.
-    pub fn stores_complex_colors_lossily(&self) -> bool {
-        % if product == "gecko":
-        matches!(*self,
-            % for property in data.longhands:
-            % if property.predefined_type == "RGBAColor":
-            LonghandId::${property.camel_case} |
-            % endif
-            % endfor
-            LonghandId::BackgroundImage |
-            LonghandId::BorderImageSource |
-            LonghandId::BoxShadow |
-            LonghandId::MaskImage |
-            LonghandId::TextShadow
-        )
-        % else:
-        false
-        % endif
-    }
 }
 
 /// An iterator over all the property ids that are enabled for a given
diff --git a/components/style/values/computed/color.rs b/components/style/values/computed/color.rs
index ade384a99ad..6098ea4590e 100644
--- a/components/style/values/computed/color.rs
+++ b/components/style/values/computed/color.rs
@@ -11,14 +11,14 @@ use cssparser::{Color as CSSParserColor, RGBA};
 use std::fmt;
 use style_traits::{CssWriter, ToCss};
 
-/// Computed value type for the specified RGBAColor.
-pub type RGBAColor = RGBA;
-
 /// The computed value of the `color` property.
 pub type ColorPropertyValue = RGBA;
 
+/// The computed value of `-moz-font-smoothing-background-color`.
+pub type MozFontSmoothingBackgroundColor = RGBA;
+
 /// A computed value for `<color>`.
-pub type Color = GenericColor<RGBAColor>;
+pub type Color = GenericColor<RGBA>;
 
 impl Color {
     /// Returns a complex color value representing transparent.
diff --git a/components/style/values/computed/mod.rs b/components/style/values/computed/mod.rs
index 4c92218e69b..95a9806f359 100644
--- a/components/style/values/computed/mod.rs
+++ b/components/style/values/computed/mod.rs
@@ -43,7 +43,7 @@ pub use self::box_::{Appearance, BreakBetween, BreakWithin, Clear, Float};
 pub use self::box_::{Display, Overflow, OverflowAnchor, TransitionProperty};
 pub use self::box_::{OverflowClipBox, OverscrollBehavior, Perspective, Resize};
 pub use self::box_::{ScrollSnapAlign, ScrollSnapType, TouchAction, VerticalAlign, WillChange};
-pub use self::color::{Color, ColorOrAuto, ColorPropertyValue, RGBAColor};
+pub use self::color::{Color, ColorOrAuto, ColorPropertyValue};
 pub use self::column::ColumnCount;
 pub use self::counters::{Content, ContentItem, CounterIncrement, CounterSetOrReset};
 pub use self::easing::TimingFunction;
diff --git a/components/style/values/specified/color.rs b/components/style/values/specified/color.rs
index 00a2033ef2a..25e7af6b98b 100644
--- a/components/style/values/specified/color.rs
+++ b/components/style/values/specified/color.rs
@@ -373,15 +373,7 @@ impl ToComputedValue for Color {
     type ComputedValue = ComputedColor;
 
     fn to_computed_value(&self, context: &Context) -> ComputedColor {
-        let result = self.to_computed_color(Some(context)).unwrap();
-        if !result.is_numeric() {
-            if let Some(longhand) = context.for_non_inherited_property {
-                if longhand.stores_complex_colors_lossily() {
-                    context.rule_cache_conditions.borrow_mut().set_uncacheable();
-                }
-            }
-        }
-        result
+        self.to_computed_color(Some(context)).unwrap()
     }
 
     fn from_computed_value(computed: &ComputedColor) -> Self {
@@ -393,37 +385,33 @@ impl ToComputedValue for Color {
     }
 }
 
-/// Specified color value, but resolved to just RGBA for computed value
-/// with value from color property at the same context.
+/// Specified color value for `-moz-font-smoothing-background-color`.
+///
+/// This property does not support `currentcolor`. We could drop it at
+/// parse-time, but it's not exposed to the web so it doesn't really matter.
+///
+/// We resolve it to `transparent` instead.
 #[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToCss, ToShmem)]
-pub struct RGBAColor(pub Color);
+pub struct MozFontSmoothingBackgroundColor(pub Color);
 
-impl Parse for RGBAColor {
+impl Parse for MozFontSmoothingBackgroundColor {
     fn parse<'i, 't>(
         context: &ParserContext,
         input: &mut Parser<'i, 't>,
     ) -> Result<Self, ParseError<'i>> {
-        Color::parse(context, input).map(RGBAColor)
+        Color::parse(context, input).map(MozFontSmoothingBackgroundColor)
     }
 }
 
-impl ToComputedValue for RGBAColor {
+impl ToComputedValue for MozFontSmoothingBackgroundColor {
     type ComputedValue = RGBA;
 
     fn to_computed_value(&self, context: &Context) -> RGBA {
-        self.0
-            .to_computed_value(context)
-            .to_rgba(context.style().get_color().clone_color())
+        self.0.to_computed_value(context).to_rgba(RGBA::transparent())
     }
 
     fn from_computed_value(computed: &RGBA) -> Self {
-        RGBAColor(Color::rgba(*computed))
-    }
-}
-
-impl From<Color> for RGBAColor {
-    fn from(color: Color) -> RGBAColor {
-        RGBAColor(color)
+        MozFontSmoothingBackgroundColor(Color::rgba(*computed))
     }
 }
 
diff --git a/components/style/values/specified/mod.rs b/components/style/values/specified/mod.rs
index 30f80fd44c2..93f9eca23b6 100644
--- a/components/style/values/specified/mod.rs
+++ b/components/style/values/specified/mod.rs
@@ -42,7 +42,7 @@ pub use self::box_::{Clear, Float, Overflow, OverflowAnchor};
 pub use self::box_::{OverflowClipBox, OverscrollBehavior, Perspective, Resize};
 pub use self::box_::{ScrollSnapAlign, ScrollSnapType};
 pub use self::box_::{TouchAction, TransitionProperty, VerticalAlign, WillChange};
-pub use self::color::{Color, ColorOrAuto, ColorPropertyValue, RGBAColor};
+pub use self::color::{Color, ColorOrAuto, ColorPropertyValue};
 pub use self::column::ColumnCount;
 pub use self::counters::{Content, ContentItem, CounterIncrement, CounterSetOrReset};
 pub use self::easing::TimingFunction;

From 369acffea8effcbeaff5b3ea839a4362943b8368 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Emilio=20Cobos=20=C3=81lvarez?= <emilio@crisal.io>
Date: Thu, 4 Apr 2019 23:04:50 +0000
Subject: [PATCH 39/59] style: Make color and text-decoration-line not early
 properties.

The text-decoration-line is a drive-by thing, but I can put it in a separate
patch if you want. It was needed for Servo (to compute
-servo-text-decorations-in-effect), but I moved Servo away from that model a
while ago.

Differential Revision: https://phabricator.services.mozilla.com/D26254
---
 components/style/properties/properties.mako.rs | 11 -----------
 1 file changed, 11 deletions(-)

diff --git a/components/style/properties/properties.mako.rs b/components/style/properties/properties.mako.rs
index 99a91179150..bb9a9ef64c9 100644
--- a/components/style/properties/properties.mako.rs
+++ b/components/style/properties/properties.mako.rs
@@ -1270,17 +1270,6 @@ impl LonghandId {
             LonghandId::FontStyle |
             LonghandId::FontFamily |
 
-            // Needed to resolve currentcolor at computed value time properly.
-            //
-            // FIXME(emilio): All the properties should be moved to currentcolor
-            // as a computed-value (and thus resolving it at used-value time).
-            //
-            // This would allow this property to go away from this list.
-            LonghandId::Color |
-
-            // FIXME(emilio): There's no reason for this afaict, nuke it.
-            LonghandId::TextDecorationLine |
-
             // Needed to properly compute the writing mode, to resolve logical
             // properties, and similar stuff.
             LonghandId::WritingMode |

From ae32e4df40747c60605f64e6db1edb2e75635f08 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Emilio=20Cobos=20=C3=81lvarez?= <emilio@crisal.io>
Date: Tue, 9 Apr 2019 00:11:03 +0000
Subject: [PATCH 40/59] style: Use an explicit stack to measure rule tree
 memory usage.

A patch of mine that makes us measure the rule tree more often triggers this.

Differential Revision: https://phabricator.services.mozilla.com/D26595
---
 components/style/rule_tree/mod.rs | 23 +++++++++--------------
 1 file changed, 9 insertions(+), 14 deletions(-)

diff --git a/components/style/rule_tree/mod.rs b/components/style/rule_tree/mod.rs
index 3e2696fff9b..d653b6be99d 100644
--- a/components/style/rule_tree/mod.rs
+++ b/components/style/rule_tree/mod.rs
@@ -75,8 +75,15 @@ impl Drop for RuleTree {
 #[cfg(feature = "gecko")]
 impl MallocSizeOf for RuleTree {
     fn size_of(&self, ops: &mut MallocSizeOfOps) -> usize {
-        let mut n = unsafe { ops.malloc_size_of(self.root.ptr()) };
-        n += self.root.get().size_of(ops);
+        let mut n = 0;
+        let mut stack = SmallVec::<[_; 32]>::new();
+        stack.push(self.root.downgrade());
+
+        while let Some(node) = stack.pop() {
+            n += unsafe { ops.malloc_size_of(node.ptr()) };
+            stack.extend(unsafe { (*node.ptr()).iter_children() });
+        }
+
         n
     }
 }
@@ -947,18 +954,6 @@ impl RuleNode {
     }
 }
 
-#[cfg(feature = "gecko")]
-impl MallocSizeOf for RuleNode {
-    fn size_of(&self, ops: &mut MallocSizeOfOps) -> usize {
-        let mut n = 0;
-        for child in self.iter_children() {
-            n += unsafe { ops.malloc_size_of(child.ptr()) };
-            n += unsafe { (*child.ptr()).size_of(ops) };
-        }
-        n
-    }
-}
-
 #[derive(Clone)]
 struct WeakRuleNode {
     p: ptr::NonNull<RuleNode>,

From c3ab3f0963da8f4476c1840ff56aa029f8336fac Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Emilio=20Cobos=20=C3=81lvarez?= <emilio@crisal.io>
Date: Tue, 9 Apr 2019 09:37:26 +0000
Subject: [PATCH 41/59] style: Share more code between ToAnimatedValue and
 ToComputedValue derive.

I'm going to add a ToResolvedValue, and I don't want to add more copy-pasta.

This shouldn't change behavior.

Differential Revision: https://phabricator.services.mozilla.com/D26289
---
 components/derive_common/cg.rs               |   6 +-
 components/style_derive/to_animated_value.rs |  82 ++++-------
 components/style_derive/to_computed_value.rs | 139 ++++++++++++-------
 3 files changed, 124 insertions(+), 103 deletions(-)

diff --git a/components/derive_common/cg.rs b/components/derive_common/cg.rs
index a5f15a0358e..7a8fbc24403 100644
--- a/components/derive_common/cg.rs
+++ b/components/derive_common/cg.rs
@@ -32,8 +32,8 @@ use synstructure::{self, BindStyle, BindingInfo, VariantAst, VariantInfo};
 pub fn propagate_clauses_to_output_type(
     where_clause: &mut Option<syn::WhereClause>,
     generics: &syn::Generics,
-    trait_path: Path,
-    trait_output: Ident,
+    trait_path: &Path,
+    trait_output: &Ident,
 ) {
     let where_clause = match *where_clause {
         Some(ref mut clause) => clause,
@@ -104,7 +104,7 @@ where
     })
 }
 
-pub fn fmap_trait_output(input: &DeriveInput, trait_path: &Path, trait_output: Ident) -> Path {
+pub fn fmap_trait_output(input: &DeriveInput, trait_path: &Path, trait_output: &Ident) -> Path {
     let segment = PathSegment {
         ident: input.ident.clone(),
         arguments: PathArguments::AngleBracketed(AngleBracketedGenericArguments {
diff --git a/components/style_derive/to_animated_value.rs b/components/style_derive/to_animated_value.rs
index 17c313e1ed0..ac231be3452 100644
--- a/components/style_derive/to_animated_value.rs
+++ b/components/style_derive/to_animated_value.rs
@@ -2,64 +2,42 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
 
-use derive_common::cg;
-use proc_macro2::{Span, TokenStream};
-use syn::{DeriveInput, Ident};
+use proc_macro2::TokenStream;
+use syn::DeriveInput;
 use synstructure::BindStyle;
+use to_computed_value;
 
-pub fn derive(mut input: DeriveInput) -> TokenStream {
-    let mut where_clause = input.generics.where_clause.take();
-    cg::propagate_clauses_to_output_type(
-        &mut where_clause,
-        &input.generics,
-        parse_quote!(crate::values::animated::ToAnimatedValue),
-        parse_quote!(AnimatedValue),
-    );
-    for param in input.generics.type_params() {
-        cg::add_predicate(
-            &mut where_clause,
-            parse_quote!(#param: crate::values::animated::ToAnimatedValue),
-        );
-    }
-
-    let to_body = cg::fmap_match(
-        &input,
-        BindStyle::Move,
-        |binding| quote!(crate::values::animated::ToAnimatedValue::to_animated_value(#binding)),
-    );
-    let from_body = cg::fmap_match(
-        &input,
-        BindStyle::Move,
-        |binding| quote!(crate::values::animated::ToAnimatedValue::from_animated_value(#binding)),
-    );
-
-    input.generics.where_clause = where_clause;
-    let name = &input.ident;
-    let (impl_generics, ty_generics, where_clause) = input.generics.split_for_impl();
-    let animated_value_type = cg::fmap_trait_output(
-        &input,
-        &parse_quote!(crate::values::animated::ToAnimatedValue),
-        Ident::new("AnimatedValue", Span::call_site()),
-    );
-
-    quote! {
-        impl #impl_generics crate::values::animated::ToAnimatedValue for #name #ty_generics #where_clause {
-            type AnimatedValue = #animated_value_type;
-
-            #[allow(unused_variables)]
-            #[inline]
-            fn to_animated_value(self) -> Self::AnimatedValue {
-                match self {
-                    #to_body
-                }
-            }
-
+pub fn derive(input: DeriveInput) -> TokenStream {
+    let trait_impl = |from_body, to_body| {
+        quote! {
             #[inline]
             fn from_animated_value(animated: Self::AnimatedValue) -> Self {
                 match animated {
                     #from_body
                 }
             }
-        }
-    }
+
+            #[inline]
+            fn to_animated_value(self) -> Self::AnimatedValue {
+                match self {
+                    #to_body
+                }
+            }
+       }
+    };
+
+    // TODO(emilio): Consider optimizing away non-generic cases as well?
+    let non_generic_implementation = || None;
+
+    to_computed_value::derive_to_value(
+        input,
+        parse_quote!(crate::values::animated::ToAnimatedValue),
+        parse_quote!(AnimatedValue),
+        BindStyle::Move,
+        |_| false,
+        |binding| quote!(crate::values::animated::ToAnimatedValue::from_animated_value(#binding)),
+        |binding| quote!(crate::values::animated::ToAnimatedValue::to_animated_value(#binding)),
+        trait_impl,
+        non_generic_implementation,
+    )
 }
diff --git a/components/style_derive/to_computed_value.rs b/components/style_derive/to_computed_value.rs
index 21efae17c66..87d4f8ba014 100644
--- a/components/style_derive/to_computed_value.rs
+++ b/components/style_derive/to_computed_value.rs
@@ -3,53 +3,70 @@
  * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
 
 use derive_common::cg;
-use proc_macro2::{Span, TokenStream};
-use syn::{DeriveInput, Ident};
-use synstructure::BindStyle;
+use proc_macro2::TokenStream;
+use syn::{DeriveInput, Ident, Path};
+use synstructure::{BindStyle, BindingInfo};
 
-pub fn derive(mut input: DeriveInput) -> TokenStream {
+pub fn derive_to_value(
+    mut input: DeriveInput,
+    trait_path: Path,
+    output_type_name: Ident,
+    bind_style: BindStyle,
+    // Returns whether to apply the field bound for a given item.
+    mut field_bound: impl FnMut(&BindingInfo) -> bool,
+    // Returns a token stream of the form: trait_path::from_foo(#binding)
+    mut call_from: impl FnMut(&BindingInfo) -> TokenStream,
+    mut call_to: impl FnMut(&BindingInfo) -> TokenStream,
+    // Returns a tokenstream of the form:
+    // fn from_function_syntax(foobar) -> Baz {
+    //     #first_arg
+    // }
+    //
+    // fn to_function_syntax(foobar) -> Baz {
+    //     #second_arg
+    // }
+    mut trait_impl: impl FnMut(TokenStream, TokenStream) -> TokenStream,
+    // if this is provided, the derive for non-generic types will be simplified
+    // to this token stream, which should be the body of the impl block.
+    non_generic_implementation: impl FnOnce() -> Option<TokenStream>,
+) -> TokenStream {
     let mut where_clause = input.generics.where_clause.take();
     cg::propagate_clauses_to_output_type(
         &mut where_clause,
         &input.generics,
-        parse_quote!(crate::values::computed::ToComputedValue),
-        parse_quote!(ComputedValue),
+        &trait_path,
+        &output_type_name,
     );
     let (to_body, from_body) = {
         let params = input.generics.type_params().collect::<Vec<_>>();
         for param in &params {
             cg::add_predicate(
                 &mut where_clause,
-                parse_quote!(#param: crate::values::computed::ToComputedValue),
+                parse_quote!(#param: #trait_path),
             );
         }
 
-        let to_body = cg::fmap_match(&input, BindStyle::Ref, |binding| {
-            let attrs = cg::parse_field_attrs::<ComputedValueAttrs>(&binding.ast());
-            if attrs.field_bound {
+        let to_body = cg::fmap_match(&input, bind_style, |binding| {
+            if field_bound(&binding) {
                 let ty = &binding.ast().ty;
 
                 let output_type = cg::map_type_params(
                     ty,
                     &params,
-                    &mut |ident| parse_quote!(<#ident as crate::values::computed::ToComputedValue>::ComputedValue),
+                    &mut |ident| parse_quote!(<#ident as #trait_path>::#output_type_name),
                 );
 
                 cg::add_predicate(
                     &mut where_clause,
                     parse_quote!(
-                        #ty: crate::values::computed::ToComputedValue<ComputedValue = #output_type>
+                        #ty: #trait_path<#output_type_name = #output_type>
                     ),
                 );
             }
-            quote! {
-                crate::values::computed::ToComputedValue::to_computed_value(#binding, context)
-            }
+            call_to(&binding)
         });
-        let from_body = cg::fmap_match(&input, BindStyle::Ref, |binding| {
-            quote! {
-                crate::values::computed::ToComputedValue::from_computed_value(#binding)
-            }
+        let from_body = cg::fmap_match(&input, bind_style, |binding| {
+            call_from(&binding)
         });
 
         (to_body, from_body)
@@ -58,39 +75,44 @@ pub fn derive(mut input: DeriveInput) -> TokenStream {
     input.generics.where_clause = where_clause;
     let name = &input.ident;
     let (impl_generics, ty_generics, where_clause) = input.generics.split_for_impl();
-
     if input.generics.type_params().next().is_none() {
-        return quote! {
-            impl #impl_generics crate::values::computed::ToComputedValue for #name #ty_generics
-            #where_clause
-            {
-                type ComputedValue = Self;
-
-                #[inline]
-                fn to_computed_value(
-                    &self,
-                    _context: &crate::values::computed::Context,
-                ) -> Self::ComputedValue {
-                    std::clone::Clone::clone(self)
+        if let Some(non_generic_implementation) = non_generic_implementation() {
+            return quote! {
+                impl #impl_generics #trait_path for #name #ty_generics
+                #where_clause
+                {
+                    #non_generic_implementation
                 }
-
-                #[inline]
-                fn from_computed_value(computed: &Self::ComputedValue) -> Self {
-                    std::clone::Clone::clone(computed)
-                }
-            }
-        };
+            };
+        }
     }
 
     let computed_value_type = cg::fmap_trait_output(
         &input,
-        &parse_quote!(crate::values::computed::ToComputedValue),
-        Ident::new("ComputedValue", Span::call_site()),
+        &trait_path,
+        &output_type_name,
     );
 
+    let impl_ = trait_impl(from_body, to_body);
+
     quote! {
-        impl #impl_generics crate::values::computed::ToComputedValue for #name #ty_generics #where_clause {
-            type ComputedValue = #computed_value_type;
+        impl #impl_generics #trait_path for #name #ty_generics #where_clause {
+            type #output_type_name = #computed_value_type;
+
+            #impl_
+        }
+    }
+}
+
+pub fn derive(input: DeriveInput) -> TokenStream {
+    let trait_impl = |from_body, to_body| {
+        quote! {
+            #[inline]
+            fn from_computed_value(computed: &Self::ComputedValue) -> Self {
+                match *computed {
+                    #from_body
+                }
+            }
 
             #[allow(unused_variables)]
             #[inline]
@@ -99,15 +121,36 @@ pub fn derive(mut input: DeriveInput) -> TokenStream {
                     #to_body
                 }
             }
+       }
+    };
+
+    let non_generic_implementation = || {
+        Some(quote! {
+            type ComputedValue = Self;
+
+            #[inline]
+            fn to_computed_value(&self, _: &crate::values::computed::Context) -> Self::ComputedValue {
+                std::clone::Clone::clone(self)
+            }
 
             #[inline]
             fn from_computed_value(computed: &Self::ComputedValue) -> Self {
-                match *computed {
-                    #from_body
-                }
+                std::clone::Clone::clone(computed)
             }
-        }
-    }
+        })
+    };
+
+    derive_to_value(
+        input,
+        parse_quote!(crate::values::computed::ToComputedValue),
+        parse_quote!(ComputedValue),
+        BindStyle::Ref,
+        |binding| cg::parse_field_attrs::<ComputedValueAttrs>(&binding.ast()).field_bound,
+        |binding| quote!(crate::values::computed::ToComputedValue::from_computed_value(#binding)),
+        |binding| quote!(crate::values::computed::ToComputedValue::to_computed_value(#binding, context)),
+        trait_impl,
+        non_generic_implementation,
+    )
 }
 
 #[darling(attributes(compute), default)]

From fc0dad2074988dd6bd0ead21ed0cf7377ee68649 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Emilio=20Cobos=20=C3=81lvarez?= <emilio@crisal.io>
Date: Tue, 9 Apr 2019 01:48:18 +0000
Subject: [PATCH 42/59] style: Handle the non-generic path earlier in the
 derive code.

No need to build the match body if there are no generics. This should hopefully
save some work too.

Depends on D26289

Differential Revision: https://phabricator.services.mozilla.com/D26290
---
 components/style_derive/to_computed_value.rs | 28 +++++++++++---------
 1 file changed, 15 insertions(+), 13 deletions(-)

diff --git a/components/style_derive/to_computed_value.rs b/components/style_derive/to_computed_value.rs
index 87d4f8ba014..6010b7483cb 100644
--- a/components/style_derive/to_computed_value.rs
+++ b/components/style_derive/to_computed_value.rs
@@ -30,6 +30,21 @@ pub fn derive_to_value(
     // to this token stream, which should be the body of the impl block.
     non_generic_implementation: impl FnOnce() -> Option<TokenStream>,
 ) -> TokenStream {
+    let name = &input.ident;
+
+    if input.generics.type_params().next().is_none() {
+        if let Some(non_generic_implementation) = non_generic_implementation() {
+            let (impl_generics, ty_generics, where_clause) = input.generics.split_for_impl();
+            return quote! {
+                impl #impl_generics #trait_path for #name #ty_generics
+                #where_clause
+                {
+                    #non_generic_implementation
+                }
+            };
+        }
+    }
+
     let mut where_clause = input.generics.where_clause.take();
     cg::propagate_clauses_to_output_type(
         &mut where_clause,
@@ -73,20 +88,7 @@ pub fn derive_to_value(
     };
 
     input.generics.where_clause = where_clause;
-    let name = &input.ident;
     let (impl_generics, ty_generics, where_clause) = input.generics.split_for_impl();
-    if input.generics.type_params().next().is_none() {
-        if let Some(non_generic_implementation) = non_generic_implementation() {
-            return quote! {
-                impl #impl_generics #trait_path for #name #ty_generics
-                #where_clause
-                {
-                    #non_generic_implementation
-                }
-            };
-        }
-    }
-
     let computed_value_type = cg::fmap_trait_output(
         &input,
         &trait_path,

From a7636010ee014b152963e16215b265baa153e91e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Emilio=20Cobos=20=C3=81lvarez?= <emilio@crisal.io>
Date: Tue, 9 Apr 2019 13:34:24 +0200
Subject: [PATCH 43/59] style: Remove a redundant use statement.

---
 components/style/build_gecko.rs | 2 --
 1 file changed, 2 deletions(-)

diff --git a/components/style/build_gecko.rs b/components/style/build_gecko.rs
index 4866909899c..e51ba6bfa3f 100644
--- a/components/style/build_gecko.rs
+++ b/components/style/build_gecko.rs
@@ -339,8 +339,6 @@ mod bindings {
     }
 
     fn setup_logging() -> bool {
-        use log;
-
         struct BuildLogger {
             file: Option<Mutex<fs::File>>,
             filter: String,

From fce58015d6cb298047e05a08f9bcd465ecf08c99 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Emilio=20Cobos=20=C3=81lvarez?= <emilio@crisal.io>
Date: Tue, 9 Apr 2019 18:03:41 +0000
Subject: [PATCH 44/59] style: Cleanup unused style traversal flags.

Some of these were unused, some of them were only used in combination with
others, so I've unified them.

In particular, Forgetful and ClearAnimationOnlyDirtyDescendants were used only
together for a very specific task (the final animation traversal), so I merged
them into something that has that name.

ClearDirtyBits was unused, so I removed along with some code that would no
longer be called.

Differential Revision: https://phabricator.services.mozilla.com/D25454
---
 components/style/dom.rs             |  9 ---------
 components/style/gecko/wrapper.rs   | 10 ----------
 components/style/matching.rs        |  6 +++---
 components/style/traversal.rs       | 28 +++-------------------------
 components/style/traversal_flags.rs | 17 ++++-------------
 5 files changed, 10 insertions(+), 60 deletions(-)

diff --git a/components/style/dom.rs b/components/style/dom.rs
index 63f82a3754f..967b978bad4 100644
--- a/components/style/dom.rs
+++ b/components/style/dom.rs
@@ -642,15 +642,6 @@ pub trait TElement:
         self.unset_dirty_descendants();
     }
 
-    /// Clear all element flags related to dirtiness.
-    ///
-    /// In Gecko, this corresponds to the regular dirty descendants bit, the
-    /// animation-only dirty descendants bit, the lazy frame construction bit,
-    /// and the lazy frame construction descendants bit.
-    unsafe fn clear_dirty_bits(&self) {
-        self.unset_dirty_descendants();
-    }
-
     /// Returns true if this element is a visited link.
     ///
     /// Servo doesn't support visited styles yet.
diff --git a/components/style/gecko/wrapper.rs b/components/style/gecko/wrapper.rs
index bab4b1e2113..a1f06a679d9 100644
--- a/components/style/gecko/wrapper.rs
+++ b/components/style/gecko/wrapper.rs
@@ -1423,16 +1423,6 @@ impl<'le> TElement for GeckoElement<'le> {
         )
     }
 
-    #[inline]
-    unsafe fn clear_dirty_bits(&self) {
-        self.unset_flags(
-            ELEMENT_HAS_DIRTY_DESCENDANTS_FOR_SERVO as u32 |
-                ELEMENT_HAS_ANIMATION_ONLY_DIRTY_DESCENDANTS_FOR_SERVO as u32 |
-                NODE_DESCENDANTS_NEED_FRAMES as u32 |
-                NODE_NEEDS_FRAME as u32,
-        )
-    }
-
     fn is_visited_link(&self) -> bool {
         self.state().intersects(ElementState::IN_VISITED_STATE)
     }
diff --git a/components/style/matching.rs b/components/style/matching.rs
index b1240443dea..583e41ad82e 100644
--- a/components/style/matching.rs
+++ b/components/style/matching.rs
@@ -471,7 +471,7 @@ trait PrivateMatchMethods: TElement {
         debug!("accumulate_damage_for: {:?}", self);
         debug_assert!(!shared_context
             .traversal_flags
-            .contains(TraversalFlags::Forgetful));
+            .contains(TraversalFlags::FinalAnimationTraversal));
 
         let difference = self.compute_style_difference(old_values, new_values, pseudo);
 
@@ -723,11 +723,11 @@ pub trait MatchMethods: TElement {
             }
         }
 
-        // Don't accumulate damage if we're in a forgetful traversal.
+        // Don't accumulate damage if we're in the final animation traversal.
         if context
             .shared
             .traversal_flags
-            .contains(TraversalFlags::Forgetful)
+            .contains(TraversalFlags::FinalAnimationTraversal)
         {
             return ChildCascadeRequirement::MustCascadeChildren;
         }
diff --git a/components/style/traversal.rs b/components/style/traversal.rs
index 5ed2388ca5d..8bc57ada8b7 100644
--- a/components/style/traversal.rs
+++ b/components/style/traversal.rs
@@ -535,12 +535,6 @@ pub fn recalc_style_at<E, D, F>(
         debug_assert!(!element.has_animation_only_dirty_descendants());
     }
 
-    debug_assert!(
-        flags.for_animation_only() ||
-            !flags.contains(TraversalFlags::ClearDirtyBits) ||
-            !element.has_animation_only_dirty_descendants(),
-        "Should have cleared animation bits already"
-    );
     clear_state_after_traversing(element, data, flags);
 }
 
@@ -548,27 +542,11 @@ fn clear_state_after_traversing<E>(element: E, data: &mut ElementData, flags: Tr
 where
     E: TElement,
 {
-    // If we are in a forgetful traversal, drop the existing restyle
-    // data here, since we won't need to perform a post-traversal to pick up
-    // any change hints.
-    if flags.contains(TraversalFlags::Forgetful) {
+    if flags.intersects(TraversalFlags::FinalAnimationTraversal) {
+        debug_assert!(flags.for_animation_only());
         data.clear_restyle_flags_and_damage();
-    }
-
-    // Clear dirty bits as appropriate.
-    if flags.for_animation_only() {
-        if flags.intersects(
-            TraversalFlags::ClearDirtyBits | TraversalFlags::ClearAnimationOnlyDirtyDescendants,
-        ) {
-            unsafe {
-                element.unset_animation_only_dirty_descendants();
-            }
-        }
-    } else if flags.contains(TraversalFlags::ClearDirtyBits) {
-        // The animation traversal happens first, so we don't need to guard against
-        // clearing the animation bit on the regular traversal.
         unsafe {
-            element.clear_dirty_bits();
+            element.unset_animation_only_dirty_descendants();
         }
     }
 }
diff --git a/components/style/traversal_flags.rs b/components/style/traversal_flags.rs
index a9a2acbf555..0987230ed02 100644
--- a/components/style/traversal_flags.rs
+++ b/components/style/traversal_flags.rs
@@ -16,15 +16,9 @@ bitflags! {
         /// Traverse and update all elements with CSS animations since
         /// @keyframes rules may have changed. Triggered by CSS rule changes.
         const ForCSSRuleChanges = 1 << 1;
-        /// A forgetful traversal ignores the previous state of the frame tree, and
-        /// thus does not compute damage or maintain other state describing the styles
-        /// pre-traversal. A forgetful traversal is usually the right thing if you
-        /// aren't going to do a post-traversal.
-        const Forgetful = 1 << 3;
-        /// Clears all the dirty bits on the elements traversed.
-        const ClearDirtyBits = 1 << 5;
-        /// Clears the animation-only dirty descendants bit in the subtree.
-        const ClearAnimationOnlyDirtyDescendants = 1 << 6;
+        /// The final animation-only traversal, which shouldn't really care about other
+        /// style changes anymore.
+        const FinalAnimationTraversal = 1 << 2;
         /// Allows the traversal to run in parallel if there are sufficient cores on
         /// the machine.
         const ParallelTraversal = 1 << 7;
@@ -58,10 +52,7 @@ pub fn assert_traversal_flags_match() {
     check_traversal_flags! {
         ServoTraversalFlags_AnimationOnly => TraversalFlags::AnimationOnly,
         ServoTraversalFlags_ForCSSRuleChanges => TraversalFlags::ForCSSRuleChanges,
-        ServoTraversalFlags_Forgetful => TraversalFlags::Forgetful,
-        ServoTraversalFlags_ClearDirtyBits => TraversalFlags::ClearDirtyBits,
-        ServoTraversalFlags_ClearAnimationOnlyDirtyDescendants =>
-            TraversalFlags::ClearAnimationOnlyDirtyDescendants,
+        ServoTraversalFlags_FinalAnimationTraversal => TraversalFlags::FinalAnimationTraversal,
         ServoTraversalFlags_ParallelTraversal => TraversalFlags::ParallelTraversal,
         ServoTraversalFlags_FlushThrottledAnimations => TraversalFlags::FlushThrottledAnimations,
     }

From 9b66f452cb2f4ae1f57db53672e9d70703eebe59 Mon Sep 17 00:00:00 2001
From: Mats Palmgren <mats@mozilla.com>
Date: Tue, 9 Apr 2019 23:01:44 +0200
Subject: [PATCH 45/59] style: Remove a note about <li value> style mapping
 that is no longer true.

Differential Revision: https://phabricator.services.mozilla.com/D26814
---
 components/style/style_adjuster.rs | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/components/style/style_adjuster.rs b/components/style/style_adjuster.rs
index 91e4bba992b..e0efe35c86f 100644
--- a/components/style/style_adjuster.rs
+++ b/components/style/style_adjuster.rs
@@ -740,9 +740,7 @@ impl<'a, 'b: 'a> StyleAdjuster<'a, 'b> {
         if self.style.pseudo.is_some() {
             return;
         }
-        // Note that we map <li value=INTEGER> to 'counter-set: list-item INTEGER;
-        // counter-increment: list-item 0;' so we'll return here unless the author
-        // explicitly specified something else.
+
         let increments = self.style.get_counters().clone_counter_increment();
         if increments.iter().any(|i| i.name.0 == atom!("list-item")) {
             return;

From 6ac777ebf22e2d619f5ffe7a253b27b7d104ccf4 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Emilio=20Cobos=20=C3=81lvarez?= <emilio@crisal.io>
Date: Wed, 10 Apr 2019 12:10:11 +0000
Subject: [PATCH 46/59] style: Add derive code for a new ToResolvedValue trait,
 and a few trivial implementations.

Differential Revision: https://phabricator.services.mozilla.com/D26782
---
 components/style/values/resolved/mod.rs      | 208 +++++++++++++++++++
 components/style_derive/to_resolved_value.rs |  69 ++++++
 2 files changed, 277 insertions(+)
 create mode 100644 components/style/values/resolved/mod.rs
 create mode 100644 components/style_derive/to_resolved_value.rs

diff --git a/components/style/values/resolved/mod.rs b/components/style/values/resolved/mod.rs
new file mode 100644
index 00000000000..8d5aa221157
--- /dev/null
+++ b/components/style/values/resolved/mod.rs
@@ -0,0 +1,208 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+//! Resolved values. These are almost always computed values, but in some cases
+//! there are used values.
+
+use cssparser;
+use smallvec::SmallVec;
+use crate::properties::ComputedValues;
+use crate::values::computed;
+
+/// Information needed to resolve a given value.
+pub struct Context<'a> {
+    /// The style we're resolving for. This is useful to resolve currentColor.
+    pub style: &'a ComputedValues,
+    // TODO(emilio): Add layout box information, and maybe property-specific
+    // information?
+}
+
+/// A trait to represent the conversion between resolved and resolved values.
+///
+/// This trait is derivable with `#[derive(ToResolvedValue)]`.
+///
+/// The deriving code assumes that if the type isn't generic, then the trait can
+/// be implemented as simple move. This means that a manual implementation with
+/// `ResolvedValue = Self` is bogus if it returns anything else than a clone.
+pub trait ToResolvedValue {
+    /// The resolved value type we're going to be converted to.
+    type ResolvedValue;
+
+    /// Convert a resolved value to a resolved value.
+    fn to_resolved_value(self, context: &Context) -> Self::ResolvedValue;
+
+    /// Convert a resolved value to resolved value form.
+    fn from_resolved_value(resolved: Self::ResolvedValue) -> Self;
+}
+
+macro_rules! trivial_to_resolved_value {
+    ($ty:ty) => {
+        impl $crate::values::resolved::ToResolvedValue for $ty {
+            type ResolvedValue = Self;
+
+            #[inline]
+            fn to_resolved_value(self, _: &Context) -> Self {
+                self
+            }
+
+            #[inline]
+            fn from_resolved_value(resolved: Self::ResolvedValue) -> Self {
+                resolved
+            }
+        }
+    };
+}
+
+trivial_to_resolved_value!(());
+trivial_to_resolved_value!(bool);
+trivial_to_resolved_value!(f32);
+trivial_to_resolved_value!(i32);
+trivial_to_resolved_value!(u8);
+trivial_to_resolved_value!(i8);
+trivial_to_resolved_value!(u16);
+trivial_to_resolved_value!(u32);
+#[cfg(feature = "servo")]
+trivial_to_resolved_value!(Prefix);
+trivial_to_resolved_value!(String);
+trivial_to_resolved_value!(Box<str>);
+trivial_to_resolved_value!(cssparser::RGBA);
+trivial_to_resolved_value!(crate::Atom);
+trivial_to_resolved_value!(app_units::Au);
+trivial_to_resolved_value!(computed::url::ComputedUrl);
+trivial_to_resolved_value!(computed::url::ComputedImageUrl);
+
+impl<A, B> ToResolvedValue for (A, B)
+where
+    A: ToResolvedValue,
+    B: ToResolvedValue,
+{
+    type ResolvedValue = (
+        <A as ToResolvedValue>::ResolvedValue,
+        <B as ToResolvedValue>::ResolvedValue,
+    );
+
+    #[inline]
+    fn to_resolved_value(self, context: &Context) -> Self::ResolvedValue {
+        (
+            self.0.to_resolved_value(context),
+            self.1.to_resolved_value(context),
+        )
+    }
+
+    #[inline]
+    fn from_resolved_value(resolved: Self::ResolvedValue) -> Self {
+        (
+            A::from_resolved_value(resolved.0),
+            B::from_resolved_value(resolved.1),
+        )
+    }
+}
+
+impl<T> ToResolvedValue for Option<T>
+where
+    T: ToResolvedValue,
+{
+    type ResolvedValue = Option<<T as ToResolvedValue>::ResolvedValue>;
+
+    #[inline]
+    fn to_resolved_value(self, context: &Context) -> Self::ResolvedValue {
+        self.map(|item| item.to_resolved_value(context))
+    }
+
+    #[inline]
+    fn from_resolved_value(resolved: Self::ResolvedValue) -> Self {
+        resolved.map(T::from_resolved_value)
+    }
+}
+
+impl<T> ToResolvedValue for SmallVec<[T; 1]>
+where
+    T: ToResolvedValue,
+{
+    type ResolvedValue = SmallVec<[<T as ToResolvedValue>::ResolvedValue; 1]>;
+
+    #[inline]
+    fn to_resolved_value(self, context: &Context) -> Self::ResolvedValue {
+        self.into_iter()
+            .map(|item| item.to_resolved_value(context))
+            .collect()
+    }
+
+    #[inline]
+    fn from_resolved_value(resolved: Self::ResolvedValue) -> Self {
+        resolved.into_iter().map(T::from_resolved_value).collect()
+    }
+}
+
+impl<T> ToResolvedValue for Vec<T>
+where
+    T: ToResolvedValue,
+{
+    type ResolvedValue = Vec<<T as ToResolvedValue>::ResolvedValue>;
+
+    #[inline]
+    fn to_resolved_value(self, context: &Context) -> Self::ResolvedValue {
+        self.into_iter()
+            .map(|item| item.to_resolved_value(context))
+            .collect()
+    }
+
+    #[inline]
+    fn from_resolved_value(resolved: Self::ResolvedValue) -> Self {
+        resolved.into_iter().map(T::from_resolved_value).collect()
+    }
+}
+
+impl<T> ToResolvedValue for Box<T>
+where
+    T: ToResolvedValue,
+{
+    type ResolvedValue = Box<<T as ToResolvedValue>::ResolvedValue>;
+
+    #[inline]
+    fn to_resolved_value(self, context: &Context) -> Self::ResolvedValue {
+        Box::new(T::to_resolved_value(*self, context))
+    }
+
+    #[inline]
+    fn from_resolved_value(resolved: Self::ResolvedValue) -> Self {
+        Box::new(T::from_resolved_value(*resolved))
+    }
+}
+
+impl<T> ToResolvedValue for Box<[T]>
+where
+    T: ToResolvedValue,
+{
+    type ResolvedValue = Box<[<T as ToResolvedValue>::ResolvedValue]>;
+
+    #[inline]
+    fn to_resolved_value(self, context: &Context) -> Self::ResolvedValue {
+        Vec::from(self).to_resolved_value(context).into_boxed_slice()
+    }
+
+    #[inline]
+    fn from_resolved_value(resolved: Self::ResolvedValue) -> Self {
+        Vec::from_resolved_value(Vec::from(resolved)).into_boxed_slice()
+    }
+}
+
+
+/// A resolved color value is an rgba color, with currentcolor resolved.
+pub type Color = cssparser::RGBA;
+
+impl ToResolvedValue for computed::Color {
+    type ResolvedValue = Color;
+
+    #[inline]
+    fn to_resolved_value(self, context: &Context) -> Self::ResolvedValue {
+        context.style.resolve_color(self)
+    }
+
+    #[inline]
+    fn from_resolved_value(resolved: Self::ResolvedValue) -> Self {
+        use crate::values::generics::color::Color as GenericColor;
+        GenericColor::Numeric(resolved)
+    }
+}
diff --git a/components/style_derive/to_resolved_value.rs b/components/style_derive/to_resolved_value.rs
new file mode 100644
index 00000000000..70d3f71876f
--- /dev/null
+++ b/components/style_derive/to_resolved_value.rs
@@ -0,0 +1,69 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+use derive_common::cg;
+use proc_macro2::TokenStream;
+use syn::DeriveInput;
+use synstructure::BindStyle;
+use to_computed_value;
+
+pub fn derive(input: DeriveInput) -> TokenStream {
+    let trait_impl = |from_body, to_body| {
+        quote! {
+            #[inline]
+            fn from_resolved_value(resolved: Self::ResolvedValue) -> Self {
+                match resolved {
+                    #from_body
+                }
+            }
+
+            #[inline]
+            fn to_resolved_value(
+                self,
+                context: &crate::values::resolved::Context,
+            ) -> Self::ResolvedValue {
+                match self {
+                    #to_body
+                }
+            }
+       }
+    };
+
+    let non_generic_implementation = || {
+        Some(quote! {
+            type ResolvedValue = Self;
+
+            #[inline]
+            fn from_resolved_value(resolved: Self::ResolvedValue) -> Self {
+                resolved
+            }
+
+            #[inline]
+            fn to_resolved_value(
+                self,
+                context: &crate::values::resolved::Context,
+            ) -> Self {
+                self
+            }
+        })
+    };
+
+    to_computed_value::derive_to_value(
+        input,
+        parse_quote!(crate::values::resolved::ToResolvedValue),
+        parse_quote!(ResolvedValue),
+        BindStyle::Move,
+        |binding| cg::parse_field_attrs::<ResolvedValueAttrs>(&binding.ast()).field_bound,
+        |binding| quote!(crate::values::resolved::ToResolvedValue::from_resolved_value(#binding)),
+        |binding| quote!(crate::values::resolved::ToResolvedValue::to_resolved_value(#binding, context)),
+        trait_impl,
+        non_generic_implementation,
+    )
+}
+
+#[darling(attributes(resolve), default)]
+#[derive(Default, FromField)]
+struct ResolvedValueAttrs {
+    field_bound: bool,
+}

From a47dcb570713b44a9782024a29de1aba1e6726e4 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Emilio=20Cobos=20=C3=81lvarez?= <emilio@crisal.io>
Date: Wed, 10 Apr 2019 12:10:26 +0000
Subject: [PATCH 47/59] style: Derive ToResolvedValue.

Differential Revision: https://phabricator.services.mozilla.com/D26783
---
 components/style/macros.rs                    |  1 +
 components/style/properties/helpers.mako.rs   | 43 ++++++++++++++++---
 components/style/values/computed/align.rs     |  2 +-
 components/style/values/computed/angle.rs     |  2 +-
 components/style/values/computed/box.rs       |  4 +-
 components/style/values/computed/font.rs      | 23 +++++-----
 components/style/values/computed/image.rs     |  2 +-
 components/style/values/computed/length.rs    |  4 +-
 components/style/values/computed/mod.rs       |  2 +-
 .../style/values/computed/percentage.rs       |  1 +
 components/style/values/computed/text.rs      |  9 ++--
 components/style/values/computed/time.rs      |  2 +-
 .../style/values/generics/background.rs       |  1 +
 .../style/values/generics/basic_shape.rs      | 12 ++++++
 components/style/values/generics/border.rs    |  5 +++
 components/style/values/generics/box.rs       | 12 +++++-
 components/style/values/generics/color.rs     |  1 +
 components/style/values/generics/column.rs    |  1 +
 components/style/values/generics/counters.rs  | 36 ++++++++++++++--
 components/style/values/generics/easing.rs    | 14 +++++-
 components/style/values/generics/effects.rs   |  3 ++
 components/style/values/generics/flex.rs      |  1 +
 components/style/values/generics/font.rs      | 34 +++++++++++++--
 components/style/values/generics/gecko.rs     | 14 +++++-
 components/style/values/generics/grid.rs      | 35 ++++++++++++---
 components/style/values/generics/image.rs     | 22 +++++-----
 components/style/values/generics/length.rs    |  4 ++
 components/style/values/generics/mod.rs       |  7 ++-
 components/style/values/generics/position.rs  |  2 +
 components/style/values/generics/rect.rs      |  1 +
 components/style/values/generics/size.rs      |  1 +
 components/style/values/generics/svg.rs       |  5 +++
 components/style/values/generics/text.rs      |  2 +
 components/style/values/generics/transform.rs | 24 +++++++++--
 components/style/values/generics/ui.rs        |  5 ++-
 components/style/values/generics/url.rs       |  1 +
 components/style/values/mod.rs                |  8 ++--
 components/style/values/specified/align.rs    | 16 +++----
 .../style/values/specified/background.rs      |  3 +-
 components/style/values/specified/border.rs   |  3 +-
 components/style/values/specified/box.rs      | 34 +++++++++++----
 components/style/values/specified/font.rs     | 17 ++++----
 components/style/values/specified/list.rs     |  7 +--
 components/style/values/specified/mod.rs      |  2 +-
 components/style/values/specified/motion.rs   |  1 +
 components/style/values/specified/outline.rs  |  1 +
 components/style/values/specified/position.rs | 12 +++---
 components/style/values/specified/svg.rs      |  4 +-
 components/style/values/specified/svg_path.rs |  1 +
 components/style/values/specified/table.rs    |  1 +
 components/style/values/specified/text.rs     |  8 +++-
 components/style/values/specified/ui.rs       |  4 +-
 components/style_derive/lib.rs                |  7 +++
 53 files changed, 359 insertions(+), 108 deletions(-)

diff --git a/components/style/macros.rs b/components/style/macros.rs
index 654053c140f..22f1966071b 100644
--- a/components/style/macros.rs
+++ b/components/style/macros.rs
@@ -80,6 +80,7 @@ macro_rules! define_keyword_type {
             ToAnimatedZero,
             ToComputedValue,
             ToCss,
+            ToResolvedValue,
             ToShmem,
         )]
         pub struct $name;
diff --git a/components/style/properties/helpers.mako.rs b/components/style/properties/helpers.mako.rs
index 06ffc2ebc41..c441268975d 100644
--- a/components/style/properties/helpers.mako.rs
+++ b/components/style/properties/helpers.mako.rs
@@ -128,8 +128,15 @@
             % if separator == "Comma":
             #[css(comma)]
             % endif
-            #[derive(Clone, Debug, MallocSizeOf, PartialEq, ToAnimatedValue,
-                     ToCss)]
+            #[derive(
+                Clone,
+                Debug,
+                MallocSizeOf,
+                PartialEq,
+                ToAnimatedValue,
+                ToResolvedValue,
+                ToCss,
+            )]
             pub struct List<T>(
                 % if not allow_empty:
                 #[css(iterable)]
@@ -425,8 +432,20 @@
 
         pub mod computed_value {
             #[cfg_attr(feature = "servo", derive(Deserialize, Serialize))]
-            #[derive(Clone, Copy, Debug, Eq, Hash, MallocSizeOf, Parse,
-                     PartialEq, SpecifiedValueInfo, ToCss, ToShmem)]
+            #[derive(
+                Clone,
+                Copy,
+                Debug,
+                Eq,
+                Hash,
+                MallocSizeOf,
+                Parse,
+                PartialEq,
+                SpecifiedValueInfo,
+                ToCss,
+                ToResolvedValue,
+                ToShmem,
+            )]
             pub enum T {
             % for value in keyword.values_for(product):
                 ${to_camel_case(value)},
@@ -588,8 +607,18 @@
         </%def>
         % if extra_specified:
             #[cfg_attr(feature = "servo", derive(Deserialize, Serialize))]
-            #[derive(Clone, Copy, Debug, Eq, MallocSizeOf, Parse, PartialEq,
-                     SpecifiedValueInfo, ToCss, ToShmem)]
+            #[derive(
+                Clone,
+                Copy,
+                Debug,
+                Eq,
+                MallocSizeOf,
+                Parse,
+                PartialEq,
+                SpecifiedValueInfo,
+                ToCss,
+                ToShmem,
+            )]
             pub enum SpecifiedValue {
                 ${variants(keyword.values_for(product) + extra_specified.split(), bool(extra_specified))}
             }
@@ -598,7 +627,7 @@
         % endif
         pub mod computed_value {
             #[cfg_attr(feature = "servo", derive(Deserialize, Serialize))]
-            #[derive(Clone, Copy, Debug, Eq, MallocSizeOf, PartialEq, ToCss)]
+            #[derive(Clone, Copy, Debug, Eq, MallocSizeOf, PartialEq, ToCss, ToResolvedValue)]
             % if not extra_specified:
             #[derive(Parse, SpecifiedValueInfo, ToComputedValue, ToShmem)]
             % endif
diff --git a/components/style/values/computed/align.rs b/components/style/values/computed/align.rs
index 739b70c765a..ea6088db5d5 100644
--- a/components/style/values/computed/align.rs
+++ b/components/style/values/computed/align.rs
@@ -33,7 +33,7 @@ pub use super::specified::{AlignSelf, JustifySelf};
 /// sucks :(.
 ///
 /// See the discussion in https://bugzil.la/1384542.
-#[derive(Clone, Copy, Debug, Eq, PartialEq, ToCss)]
+#[derive(Clone, Copy, Debug, Eq, PartialEq, ToCss, ToResolvedValue)]
 pub struct JustifyItems {
     /// The specified value for the property. Can contain the bare `legacy`
     /// keyword.
diff --git a/components/style/values/computed/angle.rs b/components/style/values/computed/angle.rs
index 76e44575dfb..1ce1a7fd34d 100644
--- a/components/style/values/computed/angle.rs
+++ b/components/style/values/computed/angle.rs
@@ -14,7 +14,7 @@ use style_traits::{CssWriter, ToCss};
 
 /// A computed angle in degrees.
 #[cfg_attr(feature = "servo", derive(Deserialize, Serialize))]
-#[derive(Add, Animate, Clone, Copy, Debug, MallocSizeOf, PartialEq, PartialOrd, ToAnimatedZero)]
+#[derive(Add, Animate, Clone, Copy, Debug, MallocSizeOf, PartialEq, PartialOrd, ToAnimatedZero, ToResolvedValue)]
 pub struct Angle(CSSFloat);
 
 impl ToCss for Angle {
diff --git a/components/style/values/computed/box.rs b/components/style/values/computed/box.rs
index decba9f342f..1fb92bec13a 100644
--- a/components/style/values/computed/box.rs
+++ b/components/style/values/computed/box.rs
@@ -49,6 +49,7 @@ pub type Perspective = GenericPerspective<NonNegativeLength>;
     PartialEq,
     SpecifiedValueInfo,
     ToCss,
+    ToResolvedValue,
 )]
 #[repr(u8)]
 /// A computed value for the `float` property.
@@ -118,6 +119,7 @@ impl ToComputedValue for SpecifiedFloat {
     PartialEq,
     SpecifiedValueInfo,
     ToCss,
+    ToResolvedValue,
 )]
 /// A computed value for the `clear` property.
 pub enum Clear {
@@ -178,7 +180,7 @@ impl ToComputedValue for SpecifiedClear {
 /// A computed value for the `resize` property.
 #[allow(missing_docs)]
 #[cfg_attr(feature = "servo", derive(Deserialize, Serialize))]
-#[derive(Clone, Copy, Debug, Eq, Hash, MallocSizeOf, Parse, PartialEq, ToCss)]
+#[derive(Clone, Copy, Debug, Eq, Hash, MallocSizeOf, Parse, PartialEq, ToCss, ToResolvedValue)]
 #[repr(u8)]
 pub enum Resize {
     None,
diff --git a/components/style/values/computed/font.rs b/components/style/values/computed/font.rs
index d332cf4d873..152bbcc0d4b 100644
--- a/components/style/values/computed/font.rs
+++ b/components/style/values/computed/font.rs
@@ -40,7 +40,7 @@ pub use crate::values::specified::font::{XLang, XTextZoom};
 /// https://drafts.csswg.org/css-fonts-4/#propdef-font-weight
 ///
 /// This is effectively just a `Number`.
-#[derive(Clone, ComputeSquaredDistance, Copy, Debug, MallocSizeOf, PartialEq, ToCss)]
+#[derive(Clone, ComputeSquaredDistance, Copy, Debug, MallocSizeOf, PartialEq, ToCss, ToResolvedValue)]
 #[cfg_attr(feature = "servo", derive(Deserialize, Serialize))]
 pub struct FontWeight(pub Number);
 
@@ -74,6 +74,7 @@ impl ToAnimatedValue for FontWeight {
     PartialEq,
     ToAnimatedZero,
     ToCss,
+    ToResolvedValue,
 )]
 /// The computed value of font-size
 pub struct FontSize {
@@ -174,7 +175,7 @@ impl ToAnimatedValue for FontSize {
     }
 }
 
-#[derive(Clone, Debug, Eq, PartialEq)]
+#[derive(Clone, Debug, Eq, PartialEq, ToResolvedValue)]
 #[cfg_attr(feature = "servo", derive(Hash, MallocSizeOf))]
 /// Specifies a prioritized list of font family names or generic family names.
 pub struct FontFamily {
@@ -221,7 +222,7 @@ impl ToCss for FontFamily {
     }
 }
 
-#[derive(Clone, Debug, Eq, Hash, MallocSizeOf, PartialEq, ToShmem)]
+#[derive(Clone, Debug, Eq, Hash, MallocSizeOf, PartialEq, ToResolvedValue, ToShmem)]
 #[cfg_attr(feature = "servo", derive(Deserialize, Serialize))]
 /// The name of a font family of choice
 pub struct FamilyName {
@@ -264,7 +265,7 @@ impl ToCss for FamilyName {
     }
 }
 
-#[derive(Clone, Copy, Debug, Eq, Hash, MallocSizeOf, PartialEq, ToShmem)]
+#[derive(Clone, Copy, Debug, Eq, Hash, MallocSizeOf, PartialEq, ToResolvedValue, ToShmem)]
 #[cfg_attr(feature = "servo", derive(Deserialize, Serialize))]
 /// Font family names must either be given quoted as strings,
 /// or unquoted as a sequence of one or more identifiers.
@@ -279,7 +280,7 @@ pub enum FontFamilyNameSyntax {
     Identifiers,
 }
 
-#[derive(Clone, Debug, Eq, MallocSizeOf, PartialEq, ToCss)]
+#[derive(Clone, Debug, Eq, MallocSizeOf, PartialEq, ToCss, ToResolvedValue)]
 #[cfg_attr(feature = "servo", derive(Deserialize, Serialize, Hash))]
 /// A set of faces that vary in weight, width or slope.
 pub enum SingleFontFamily {
@@ -294,7 +295,7 @@ pub enum SingleFontFamily {
 /// The order here is important, if you change it make sure that
 /// `gfxPlatformFontList.h`s ranged array and `gfxFontFamilyList`'s
 /// sSingleGenerics are updated as well.
-#[derive(Clone, Copy, Debug, Eq, Hash, MallocSizeOf, PartialEq, Parse, ToCss)]
+#[derive(Clone, Copy, Debug, Eq, Hash, MallocSizeOf, PartialEq, Parse, ToCss, ToResolvedValue)]
 #[repr(u8)]
 #[allow(missing_docs)]
 pub enum GenericFontFamily {
@@ -384,7 +385,7 @@ impl SingleFontFamily {
 }
 
 #[cfg(feature = "servo")]
-#[derive(Clone, Debug, Eq, Hash, MallocSizeOf, PartialEq)]
+#[derive(Clone, Debug, Eq, Hash, MallocSizeOf, PartialEq, ToResolvedValue)]
 /// A list of SingleFontFamily
 pub struct FontFamilyList(Box<[SingleFontFamily]>);
 
@@ -546,7 +547,7 @@ impl<'a> Iterator for FontFamilyNameIter<'a> {
 }
 
 /// Preserve the readability of text when font fallback occurs
-#[derive(Animate, Clone, ComputeSquaredDistance, Copy, Debug, MallocSizeOf, PartialEq, ToCss)]
+#[derive(Animate, Clone, ComputeSquaredDistance, Copy, Debug, MallocSizeOf, PartialEq, ToCss, ToResolvedValue)]
 pub enum FontSizeAdjust {
     #[animation(error)]
     /// None variant
@@ -627,7 +628,7 @@ pub type FontVariationSettings = FontSettings<VariationValue<Number>>;
 /// OpenType "language system" tag, so we should be able to compute
 /// it and store it as a 32-bit integer
 /// (see http://www.microsoft.com/typography/otspec/languagetags.htm).
-#[derive(Clone, Copy, Debug, Eq, MallocSizeOf, PartialEq)]
+#[derive(Clone, Copy, Debug, Eq, MallocSizeOf, PartialEq, ToResolvedValue)]
 #[repr(C)]
 pub struct FontLanguageOverride(pub u32);
 
@@ -733,7 +734,7 @@ impl ToComputedValue for specified::MozScriptLevel {
 
 /// A wrapper over an `Angle`, that handles clamping to the appropriate range
 /// for `font-style` animation.
-#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, ToCss)]
+#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, ToCss, ToResolvedValue)]
 #[cfg_attr(feature = "servo", derive(Deserialize, Serialize))]
 pub struct FontStyleAngle(pub Angle);
 
@@ -830,7 +831,7 @@ impl ToCss for FontStyle {
 /// A value for the font-stretch property per:
 ///
 /// https://drafts.csswg.org/css-fonts-4/#propdef-font-stretch
-#[derive(Clone, ComputeSquaredDistance, Copy, Debug, MallocSizeOf, PartialEq, ToCss)]
+#[derive(Clone, ComputeSquaredDistance, Copy, Debug, MallocSizeOf, PartialEq, ToCss, ToResolvedValue)]
 #[cfg_attr(feature = "servo", derive(Deserialize, Serialize))]
 pub struct FontStretch(pub NonNegativePercentage);
 
diff --git a/components/style/values/computed/image.rs b/components/style/values/computed/image.rs
index a77da59dda3..4070e51815a 100644
--- a/components/style/values/computed/image.rs
+++ b/components/style/values/computed/image.rs
@@ -36,7 +36,7 @@ pub type GradientKind =
     generic::GradientKind<LineDirection, Length, LengthPercentage, Position, Angle>;
 
 /// A computed gradient line direction.
-#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq)]
+#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, ToResolvedValue)]
 pub enum LineDirection {
     /// An angle.
     Angle(Angle),
diff --git a/components/style/values/computed/length.rs b/components/style/values/computed/length.rs
index 0fd624b5c55..92215541e8a 100644
--- a/components/style/values/computed/length.rs
+++ b/components/style/values/computed/length.rs
@@ -75,7 +75,7 @@ impl ToComputedValue for specified::Length {
 ///
 /// https://drafts.csswg.org/css-values-4/#typedef-length-percentage
 #[allow(missing_docs)]
-#[derive(Clone, Copy, Debug, MallocSizeOf, ToAnimatedZero)]
+#[derive(Clone, Copy, Debug, MallocSizeOf, ToAnimatedZero, ToResolvedValue)]
 #[repr(C)]
 pub struct LengthPercentage {
     length: Length,
@@ -608,6 +608,7 @@ impl Size {
     PartialOrd,
     ToAnimatedValue,
     ToAnimatedZero,
+    ToResolvedValue,
     ToShmem,
 )]
 #[repr(C)]
@@ -804,6 +805,7 @@ pub type NonNegativeLengthOrNumber = GenericLengthOrNumber<NonNegativeLength, No
     ToAnimatedZero,
     ToComputedValue,
     ToCss,
+    ToResolvedValue,
     ToShmem,
 )]
 #[repr(u8)]
diff --git a/components/style/values/computed/mod.rs b/components/style/values/computed/mod.rs
index 95a9806f359..f01661cbc9c 100644
--- a/components/style/values/computed/mod.rs
+++ b/components/style/values/computed/mod.rs
@@ -534,7 +534,7 @@ impl From<GreaterThanOrEqualToOneNumber> for CSSFloat {
 }
 
 #[allow(missing_docs)]
-#[derive(Clone, ComputeSquaredDistance, Copy, Debug, MallocSizeOf, PartialEq, ToCss)]
+#[derive(Clone, ComputeSquaredDistance, Copy, Debug, MallocSizeOf, PartialEq, ToCss, ToResolvedValue)]
 #[repr(C, u8)]
 pub enum NumberOrPercentage {
     Percentage(Percentage),
diff --git a/components/style/values/computed/percentage.rs b/components/style/values/computed/percentage.rs
index 68579f95fb4..c22f8ed5683 100644
--- a/components/style/values/computed/percentage.rs
+++ b/components/style/values/computed/percentage.rs
@@ -27,6 +27,7 @@ use style_traits::{CssWriter, ToCss};
     ToAnimatedValue,
     ToAnimatedZero,
     ToComputedValue,
+    ToResolvedValue,
     ToShmem,
 )]
 #[repr(C)]
diff --git a/components/style/values/computed/text.rs b/components/style/values/computed/text.rs
index db56a16a82d..2fdb1e48c4f 100644
--- a/components/style/values/computed/text.rs
+++ b/components/style/values/computed/text.rs
@@ -37,6 +37,7 @@ pub type InitialLetter = GenericInitialLetter<CSSFloat, CSSInteger>;
     PartialEq,
     ToAnimatedValue,
     ToAnimatedZero,
+    ToResolvedValue,
 )]
 pub struct LetterSpacing(pub Length);
 
@@ -102,7 +103,7 @@ impl ToComputedValue for specified::WordSpacing {
 /// A computed value for the `line-height` property.
 pub type LineHeight = GenericLineHeight<NonNegativeNumber, NonNegativeLength>;
 
-#[derive(Clone, Debug, MallocSizeOf, PartialEq)]
+#[derive(Clone, Debug, MallocSizeOf, PartialEq, ToResolvedValue)]
 /// text-overflow.
 /// When the specified value only has one side, that's the "second"
 /// side, and the sides are logical, so "second" means "end".  The
@@ -155,7 +156,7 @@ impl ToCss for TextOverflow {
 /// and similar stuff when we implement it.
 ///
 /// FIXME(emilio): Also, should be just a bitfield instead of three bytes.
-#[derive(Clone, Copy, Debug, Default, MallocSizeOf, PartialEq)]
+#[derive(Clone, Copy, Debug, Default, MallocSizeOf, PartialEq, ToResolvedValue)]
 pub struct TextDecorationsInEffect {
     /// Whether an underline is in effect.
     pub underline: bool,
@@ -193,7 +194,7 @@ impl TextDecorationsInEffect {
 }
 
 /// computed value for the text-emphasis-style property
-#[derive(Clone, Debug, MallocSizeOf, PartialEq, ToCss)]
+#[derive(Clone, Debug, MallocSizeOf, PartialEq, ToCss, ToResolvedValue)]
 pub enum TextEmphasisStyle {
     /// Keyword value for the text-emphasis-style property (`filled` `open`)
     Keyword(TextEmphasisKeywordValue),
@@ -204,7 +205,7 @@ pub enum TextEmphasisStyle {
 }
 
 /// Keyword value for the text-emphasis-style property
-#[derive(Clone, Debug, MallocSizeOf, PartialEq, ToCss)]
+#[derive(Clone, Debug, MallocSizeOf, PartialEq, ToCss, ToResolvedValue)]
 pub struct TextEmphasisKeywordValue {
     /// fill for the text-emphasis-style property
     pub fill: TextEmphasisFillMode,
diff --git a/components/style/values/computed/time.rs b/components/style/values/computed/time.rs
index be16a5939bb..5681f6fab5e 100644
--- a/components/style/values/computed/time.rs
+++ b/components/style/values/computed/time.rs
@@ -9,7 +9,7 @@ use std::fmt::{self, Write};
 use style_traits::{CssWriter, ToCss};
 
 /// A computed `<time>` value.
-#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, PartialOrd)]
+#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, PartialOrd, ToResolvedValue)]
 #[cfg_attr(feature = "servo", derive(Deserialize, Serialize))]
 pub struct Time {
     seconds: CSSFloat,
diff --git a/components/style/values/generics/background.rs b/components/style/values/generics/background.rs
index 0ea71713e37..b64fccb6051 100644
--- a/components/style/values/generics/background.rs
+++ b/components/style/values/generics/background.rs
@@ -27,6 +27,7 @@ fn width_and_height_are_auto<L>(
     ToAnimatedZero,
     ToComputedValue,
     ToCss,
+    ToResolvedValue,
     ToShmem,
 )]
 #[repr(C, u8)]
diff --git a/components/style/values/generics/basic_shape.rs b/components/style/values/generics/basic_shape.rs
index 2258ce11ade..5999e914676 100644
--- a/components/style/values/generics/basic_shape.rs
+++ b/components/style/values/generics/basic_shape.rs
@@ -31,6 +31,7 @@ pub type ClippingShape<BasicShape, Url> = ShapeSource<BasicShape, GeometryBox, U
     ToAnimatedValue,
     ToComputedValue,
     ToCss,
+    ToResolvedValue,
     ToShmem,
 )]
 pub enum GeometryBox {
@@ -59,6 +60,7 @@ pub type FloatAreaShape<BasicShape, Image> = ShapeSource<BasicShape, ShapeBox, I
     ToAnimatedValue,
     ToComputedValue,
     ToCss,
+    ToResolvedValue,
     ToShmem,
 )]
 pub enum ShapeBox {
@@ -81,6 +83,7 @@ pub enum ShapeBox {
     ToAnimatedValue,
     ToComputedValue,
     ToCss,
+    ToResolvedValue,
     ToShmem,
 )]
 pub enum ShapeSource<BasicShape, ReferenceBox, ImageOrUrl> {
@@ -107,6 +110,7 @@ pub enum ShapeSource<BasicShape, ReferenceBox, ImageOrUrl> {
     ToAnimatedValue,
     ToComputedValue,
     ToCss,
+    ToResolvedValue,
     ToShmem,
 )]
 pub enum BasicShape<H, V, LengthPercentage, NonNegativeLengthPercentage> {
@@ -141,6 +145,7 @@ pub enum BasicShape<H, V, LengthPercentage, NonNegativeLengthPercentage> {
     SpecifiedValueInfo,
     ToAnimatedValue,
     ToComputedValue,
+    ToResolvedValue,
     ToShmem,
 )]
 pub struct InsetRect<LengthPercentage, NonNegativeLengthPercentage> {
@@ -163,6 +168,7 @@ pub struct InsetRect<LengthPercentage, NonNegativeLengthPercentage> {
     SpecifiedValueInfo,
     ToAnimatedValue,
     ToComputedValue,
+    ToResolvedValue,
     ToShmem,
 )]
 pub struct Circle<H, V, NonNegativeLengthPercentage> {
@@ -184,6 +190,7 @@ pub struct Circle<H, V, NonNegativeLengthPercentage> {
     SpecifiedValueInfo,
     ToAnimatedValue,
     ToComputedValue,
+    ToResolvedValue,
     ToShmem,
 )]
 pub struct Ellipse<H, V, NonNegativeLengthPercentage> {
@@ -206,6 +213,7 @@ pub struct Ellipse<H, V, NonNegativeLengthPercentage> {
     ToAnimatedValue,
     ToComputedValue,
     ToCss,
+    ToResolvedValue,
     ToShmem,
 )]
 pub enum ShapeRadius<NonNegativeLengthPercentage> {
@@ -229,6 +237,7 @@ pub enum ShapeRadius<NonNegativeLengthPercentage> {
     ToAnimatedValue,
     ToComputedValue,
     ToCss,
+    ToResolvedValue,
     ToShmem,
 )]
 pub struct Polygon<LengthPercentage> {
@@ -250,6 +259,7 @@ pub struct Polygon<LengthPercentage> {
     ToAnimatedValue,
     ToComputedValue,
     ToCss,
+    ToResolvedValue,
     ToShmem,
 )]
 pub struct PolygonCoord<LengthPercentage>(pub LengthPercentage, pub LengthPercentage);
@@ -272,6 +282,7 @@ pub struct PolygonCoord<LengthPercentage>(pub LengthPercentage, pub LengthPercen
     ToAnimatedValue,
     ToComputedValue,
     ToCss,
+    ToResolvedValue,
     ToShmem,
 )]
 #[repr(u8)]
@@ -294,6 +305,7 @@ pub enum FillRule {
     ToAnimatedValue,
     ToComputedValue,
     ToCss,
+    ToResolvedValue,
     ToShmem,
 )]
 pub struct Path {
diff --git a/components/style/values/generics/border.rs b/components/style/values/generics/border.rs
index 4652ce5ec85..fb6f1537662 100644
--- a/components/style/values/generics/border.rs
+++ b/components/style/values/generics/border.rs
@@ -20,6 +20,7 @@ use style_traits::{CssWriter, ToCss};
     SpecifiedValueInfo,
     ToComputedValue,
     ToCss,
+    ToResolvedValue,
     ToShmem,
 )]
 pub enum BorderImageSideWidth<LengthPercentage, Number> {
@@ -41,6 +42,7 @@ pub enum BorderImageSideWidth<LengthPercentage, Number> {
     SpecifiedValueInfo,
     ToComputedValue,
     ToCss,
+    ToResolvedValue,
     ToShmem,
 )]
 #[repr(C)]
@@ -69,6 +71,7 @@ pub use self::GenericBorderImageSlice as BorderImageSlice;
     ToAnimatedZero,
     ToComputedValue,
     ToCss,
+    ToResolvedValue,
     ToShmem,
 )]
 #[repr(C)]
@@ -107,6 +110,7 @@ impl<L: Zero> Zero for BorderCornerRadius<L> {
     ToAnimatedZero,
     ToComputedValue,
     ToCss,
+    ToResolvedValue,
     ToShmem,
 )]
 #[repr(transparent)]
@@ -133,6 +137,7 @@ impl<L> BorderSpacing<L> {
     SpecifiedValueInfo,
     ToAnimatedValue,
     ToComputedValue,
+    ToResolvedValue,
     ToShmem,
 )]
 #[repr(C)]
diff --git a/components/style/values/generics/box.rs b/components/style/values/generics/box.rs
index 91f7cf31828..3e8f959f456 100644
--- a/components/style/values/generics/box.rs
+++ b/components/style/values/generics/box.rs
@@ -18,6 +18,7 @@ use crate::values::animated::ToAnimatedZero;
     SpecifiedValueInfo,
     ToComputedValue,
     ToCss,
+    ToResolvedValue,
     ToShmem,
 )]
 pub enum VerticalAlign<LengthPercentage> {
@@ -60,7 +61,15 @@ impl<L> ToAnimatedZero for VerticalAlign<L> {
 
 /// https://drafts.csswg.org/css-animations/#animation-iteration-count
 #[derive(
-    Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss, ToShmem,
+    Clone,
+    Debug,
+    MallocSizeOf,
+    PartialEq,
+    SpecifiedValueInfo,
+    ToComputedValue,
+    ToCss,
+    ToResolvedValue,
+    ToShmem,
 )]
 pub enum AnimationIterationCount<Number> {
     /// A `<number>` value.
@@ -84,6 +93,7 @@ pub enum AnimationIterationCount<Number> {
     ToAnimatedZero,
     ToComputedValue,
     ToCss,
+    ToResolvedValue,
     ToShmem,
 )]
 #[repr(C, u8)]
diff --git a/components/style/values/generics/color.rs b/components/style/values/generics/color.rs
index 5aa287baadf..0f67f4eb7ca 100644
--- a/components/style/values/generics/color.rs
+++ b/components/style/values/generics/color.rs
@@ -99,6 +99,7 @@ impl<RGBA> From<RGBA> for Color<RGBA> {
     ToAnimatedZero,
     ToComputedValue,
     ToCss,
+    ToResolvedValue,
     ToShmem,
 )]
 #[repr(C, u8)]
diff --git a/components/style/values/generics/column.rs b/components/style/values/generics/column.rs
index a70d9942ac4..4b5f0e03993 100644
--- a/components/style/values/generics/column.rs
+++ b/components/style/values/generics/column.rs
@@ -19,6 +19,7 @@
     ToAnimatedZero,
     ToComputedValue,
     ToCss,
+    ToResolvedValue,
     ToShmem,
 )]
 pub enum ColumnCount<PositiveInteger> {
diff --git a/components/style/values/generics/counters.rs b/components/style/values/generics/counters.rs
index 4ca5361520d..9da5b9140d9 100644
--- a/components/style/values/generics/counters.rs
+++ b/components/style/values/generics/counters.rs
@@ -15,7 +15,7 @@ use std::ops::Deref;
 
 /// A name / value pair for counters.
 #[derive(
-    Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss, ToShmem,
+    Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss, ToResolvedValue, ToShmem,
 )]
 pub struct CounterPair<Integer> {
     /// The name of the counter.
@@ -34,6 +34,7 @@ pub struct CounterPair<Integer> {
     SpecifiedValueInfo,
     ToComputedValue,
     ToCss,
+    ToResolvedValue,
     ToShmem,
 )]
 pub struct CounterIncrement<I>(Counters<I>);
@@ -65,6 +66,7 @@ impl<I> Deref for CounterIncrement<I> {
     SpecifiedValueInfo,
     ToComputedValue,
     ToCss,
+    ToResolvedValue,
     ToShmem,
 )]
 pub struct CounterSetOrReset<I>(Counters<I>);
@@ -90,7 +92,15 @@ impl<I> Deref for CounterSetOrReset<I> {
 ///
 /// Keyword `none` is represented by an empty vector.
 #[derive(
-    Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss, ToShmem,
+    Clone,
+    Debug,
+    MallocSizeOf,
+    PartialEq,
+    SpecifiedValueInfo,
+    ToComputedValue,
+    ToCss,
+    ToResolvedValue,
+    ToShmem,
 )]
 pub struct Counters<I>(#[css(iterable, if_empty = "none")] Box<[CounterPair<I>]>);
 
@@ -123,7 +133,16 @@ fn is_decimal(counter_type: &CounterStyleType) -> bool {
 ///
 /// https://drafts.csswg.org/css-content/#propdef-content
 #[derive(
-    Clone, Debug, Eq, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss, ToShmem,
+    Clone,
+    Debug,
+    Eq,
+    MallocSizeOf,
+    PartialEq,
+    SpecifiedValueInfo,
+    ToComputedValue,
+    ToCss,
+    ToResolvedValue,
+    ToShmem,
 )]
 pub enum Content<ImageUrl> {
     /// `normal` reserved keyword.
@@ -147,7 +166,16 @@ impl<ImageUrl> Content<ImageUrl> {
 
 /// Items for the `content` property.
 #[derive(
-    Clone, Debug, Eq, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss, ToShmem,
+    Clone,
+    Debug,
+    Eq,
+    MallocSizeOf,
+    PartialEq,
+    SpecifiedValueInfo,
+    ToComputedValue,
+    ToCss,
+    ToResolvedValue,
+    ToShmem,
 )]
 pub enum ContentItem<ImageUrl> {
     /// Literal string content.
diff --git a/components/style/values/generics/easing.rs b/components/style/values/generics/easing.rs
index 90ad530a98a..8817c3d2603 100644
--- a/components/style/values/generics/easing.rs
+++ b/components/style/values/generics/easing.rs
@@ -18,6 +18,7 @@ use crate::values::CSSFloat;
     SpecifiedValueInfo,
     ToComputedValue,
     ToCss,
+    ToResolvedValue,
     ToShmem,
 )]
 #[value_info(ty = "TIMING_FUNCTION")]
@@ -54,6 +55,7 @@ pub enum TimingFunction<Integer, Number> {
     SpecifiedValueInfo,
     ToComputedValue,
     ToCss,
+    ToResolvedValue,
     ToShmem,
 )]
 #[repr(u8)]
@@ -79,7 +81,17 @@ fn step_position_jump_enabled(_context: &ParserContext) -> bool {
 #[allow(missing_docs)]
 #[cfg_attr(feature = "servo", derive(Deserialize, Serialize))]
 #[derive(
-    Clone, Copy, Debug, Eq, MallocSizeOf, Parse, PartialEq, ToComputedValue, ToCss, ToShmem,
+    Clone,
+    Copy,
+    Debug,
+    Eq,
+    MallocSizeOf,
+    Parse,
+    PartialEq,
+    ToComputedValue,
+    ToCss,
+    ToResolvedValue,
+    ToShmem,
 )]
 #[repr(u8)]
 pub enum StepPosition {
diff --git a/components/style/values/generics/effects.rs b/components/style/values/generics/effects.rs
index 744f8ac1fe7..aa56fc1bbb3 100644
--- a/components/style/values/generics/effects.rs
+++ b/components/style/values/generics/effects.rs
@@ -16,6 +16,7 @@
     ToAnimatedValue,
     ToAnimatedZero,
     ToCss,
+    ToResolvedValue,
     ToShmem,
 )]
 pub struct BoxShadow<Color, SizeLength, BlurShapeLength, ShapeLength> {
@@ -42,6 +43,7 @@ pub struct BoxShadow<Color, SizeLength, BlurShapeLength, ShapeLength> {
     ToAnimatedValue,
     ToComputedValue,
     ToCss,
+    ToResolvedValue,
     ToShmem,
 )]
 pub enum Filter<Angle, Factor, Length, DropShadow, Url> {
@@ -95,6 +97,7 @@ pub enum Filter<Angle, Factor, Length, DropShadow, Url> {
     ToAnimatedValue,
     ToAnimatedZero,
     ToCss,
+    ToResolvedValue,
     ToShmem,
 )]
 pub struct SimpleShadow<Color, SizeLength, ShapeLength> {
diff --git a/components/style/values/generics/flex.rs b/components/style/values/generics/flex.rs
index 11b2b737902..adff13b5b42 100644
--- a/components/style/values/generics/flex.rs
+++ b/components/style/values/generics/flex.rs
@@ -19,6 +19,7 @@
     ToAnimatedZero,
     ToComputedValue,
     ToCss,
+    ToResolvedValue,
     ToShmem,
 )]
 #[repr(C)]
diff --git a/components/style/values/generics/font.rs b/components/style/values/generics/font.rs
index 36c15172490..59907ff7920 100644
--- a/components/style/values/generics/font.rs
+++ b/components/style/values/generics/font.rs
@@ -16,7 +16,15 @@ use style_traits::{SpecifiedValueInfo, StyleParseErrorKind, ToCss};
 
 /// https://drafts.csswg.org/css-fonts-4/#feature-tag-value
 #[derive(
-    Clone, Debug, Eq, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToShmem,
+    Clone,
+    Debug,
+    Eq,
+    MallocSizeOf,
+    PartialEq,
+    SpecifiedValueInfo,
+    ToComputedValue,
+    ToResolvedValue,
+    ToShmem,
 )]
 pub struct FeatureTagValue<Integer> {
     /// A four-character tag, packed into a u32 (one byte per character).
@@ -58,6 +66,7 @@ where
     SpecifiedValueInfo,
     ToComputedValue,
     ToCss,
+    ToResolvedValue,
     ToShmem,
 )]
 pub struct VariationValue<Number> {
@@ -71,7 +80,16 @@ pub struct VariationValue<Number> {
 /// A value both for font-variation-settings and font-feature-settings.
 #[css(comma)]
 #[derive(
-    Clone, Debug, Eq, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss, ToShmem,
+    Clone,
+    Debug,
+    Eq,
+    MallocSizeOf,
+    PartialEq,
+    SpecifiedValueInfo,
+    ToComputedValue,
+    ToCss,
+    ToResolvedValue,
+    ToShmem,
 )]
 pub struct FontSettings<T>(#[css(if_empty = "normal", iterable)] pub Box<[T]>);
 
@@ -109,7 +127,16 @@ impl<T: Parse> Parse for FontSettings<T> {
 ///   https://drafts.csswg.org/css-fonts-4/#descdef-font-face-font-feature-settings
 ///
 #[derive(
-    Clone, Copy, Debug, Eq, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToShmem,
+    Clone,
+    Copy,
+    Debug,
+    Eq,
+    MallocSizeOf,
+    PartialEq,
+    SpecifiedValueInfo,
+    ToComputedValue,
+    ToResolvedValue,
+    ToShmem,
 )]
 pub struct FontTag(pub u32);
 
@@ -263,6 +290,7 @@ impl Default for KeywordSize {
     SpecifiedValueInfo,
     ToAnimatedValue,
     ToAnimatedZero,
+    ToResolvedValue,
     ToShmem,
 )]
 pub enum FontStyle<Angle> {
diff --git a/components/style/values/generics/gecko.rs b/components/style/values/generics/gecko.rs
index 5a91f2e14f4..ccff3d2a76d 100644
--- a/components/style/values/generics/gecko.rs
+++ b/components/style/values/generics/gecko.rs
@@ -3,11 +3,21 @@
  * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
 
 //! Generic types for legacy Gecko-only properties that should probably be
-//! unshipped at some point in the future.
+//! un-shipped at some point in the future.
 
 /// A generic value for scroll snap points.
 #[cfg_attr(feature = "gecko", derive(MallocSizeOf))]
-#[derive(Clone, Copy, Debug, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss, ToShmem)]
+#[derive(
+    Clone,
+    Copy,
+    Debug,
+    PartialEq,
+    SpecifiedValueInfo,
+    ToComputedValue,
+    ToCss,
+    ToResolvedValue,
+    ToShmem,
+)]
 pub enum ScrollSnapPoint<LengthPercentage> {
     /// `none`
     None,
diff --git a/components/style/values/generics/grid.rs b/components/style/values/generics/grid.rs
index a3a94d3eaf5..17af16e5167 100644
--- a/components/style/values/generics/grid.rs
+++ b/components/style/values/generics/grid.rs
@@ -19,7 +19,15 @@ use style_traits::{CssWriter, ParseError, StyleParseErrorKind, ToCss};
 ///
 /// <https://drafts.csswg.org/css-grid/#typedef-grid-row-start-grid-line>
 #[derive(
-    Clone, Debug, Default, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToShmem,
+    Clone,
+    Debug,
+    Default,
+    MallocSizeOf,
+    PartialEq,
+    SpecifiedValueInfo,
+    ToComputedValue,
+    ToResolvedValue,
+    ToShmem,
 )]
 pub struct GridLine<Integer> {
     /// Flag to check whether it's a `span` keyword.
@@ -164,6 +172,7 @@ impl Parse for GridLine<specified::Integer> {
     SpecifiedValueInfo,
     ToComputedValue,
     ToCss,
+    ToResolvedValue,
     ToShmem,
 )]
 pub enum TrackKeyword {
@@ -185,6 +194,7 @@ pub enum TrackKeyword {
     SpecifiedValueInfo,
     ToComputedValue,
     ToCss,
+    ToResolvedValue,
     ToShmem,
 )]
 pub enum TrackBreadth<L> {
@@ -211,7 +221,7 @@ impl<L> TrackBreadth<L> {
 /// generic only to avoid code bloat. It only takes `<length-percentage>`
 ///
 /// <https://drafts.csswg.org/css-grid/#typedef-track-size>
-#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToShmem)]
+#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToResolvedValue, ToShmem)]
 pub enum TrackSize<L> {
     /// A flexible `<track-breadth>`
     Breadth(TrackBreadth<L>),
@@ -369,7 +379,7 @@ where
 /// The initial argument of the `repeat` function.
 ///
 /// <https://drafts.csswg.org/css-grid/#typedef-track-repeat>
-#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, ToComputedValue, ToCss, ToShmem)]
+#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, ToComputedValue, ToCss, ToResolvedValue, ToShmem)]
 pub enum RepeatCount<Integer> {
     /// A positive integer. This is allowed only for `<track-repeat>` and `<fixed-repeat>`
     Number(Integer),
@@ -404,7 +414,7 @@ impl Parse for RepeatCount<specified::Integer> {
 ///
 /// It can also hold `repeat()` function parameters, which expands into the respective
 /// values in its computed form.
-#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToShmem)]
+#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToResolvedValue, ToShmem)]
 #[css(function = "repeat")]
 pub struct TrackRepeat<L, I> {
     /// The number of times for the value to be repeated (could also be `auto-fit` or `auto-fill`)
@@ -501,6 +511,7 @@ impl<L: Clone> TrackRepeat<L, specified::Integer> {
     SpecifiedValueInfo,
     ToComputedValue,
     ToCss,
+    ToResolvedValue,
     ToShmem,
 )]
 pub enum TrackListValue<LengthPercentage, Integer> {
@@ -513,7 +524,7 @@ pub enum TrackListValue<LengthPercentage, Integer> {
 /// The type of a `<track-list>` as determined during parsing.
 ///
 /// <https://drafts.csswg.org/css-grid/#typedef-track-list>
-#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, ToComputedValue, ToShmem)]
+#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, ToComputedValue, ToResolvedValue, ToShmem)]
 pub enum TrackListType {
     /// [`<auto-track-list>`](https://drafts.csswg.org/css-grid/#typedef-auto-track-list)
     ///
@@ -535,7 +546,7 @@ pub enum TrackListType {
 /// A grid `<track-list>` type.
 ///
 /// <https://drafts.csswg.org/css-grid/#typedef-track-list>
-#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToShmem)]
+#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToShmem, ToResolvedValue)]
 pub struct TrackList<LengthPercentage, Integer> {
     /// The type of this `<track-list>` (auto, explicit or general).
     ///
@@ -609,7 +620,15 @@ impl<L: ToCss, I: ToCss> ToCss for TrackList<L, I> {
 /// `subgrid [ <line-names> | repeat(<positive-integer> | auto-fill, <line-names>+) ]+`
 /// Old spec: https://www.w3.org/TR/2015/WD-css-grid-1-20150917/#typedef-line-name-list
 #[derive(
-    Clone, Debug, Default, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToShmem,
+    Clone,
+    Debug,
+    Default,
+    MallocSizeOf,
+    PartialEq,
+    SpecifiedValueInfo,
+    ToComputedValue,
+    ToResolvedValue,
+    ToShmem,
 )]
 pub struct LineNameList {
     /// The optional `<line-name-list>`
@@ -724,6 +743,7 @@ impl ToCss for LineNameList {
     SpecifiedValueInfo,
     ToComputedValue,
     ToCss,
+    ToResolvedValue,
     ToShmem,
 )]
 pub enum GridTemplateComponent<L, I> {
@@ -733,6 +753,7 @@ pub enum GridTemplateComponent<L, I> {
     TrackList(
         #[animation(field_bound)]
         #[compute(field_bound)]
+        #[resolve(field_bound)]
         #[shmem(field_bound)]
         TrackList<L, I>,
     ),
diff --git a/components/style/values/generics/image.rs b/components/style/values/generics/image.rs
index 3f8b4f76f58..59fc260f93a 100644
--- a/components/style/values/generics/image.rs
+++ b/components/style/values/generics/image.rs
@@ -16,7 +16,7 @@ use style_traits::{CssWriter, ToCss};
 /// An [image].
 ///
 /// [image]: https://drafts.csswg.org/css-images/#image-values
-#[derive(Clone, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToShmem)]
+#[derive(Clone, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToResolvedValue, ToShmem)]
 pub enum Image<Gradient, MozImageRect, ImageUrl> {
     /// A `<url()>` image.
     Url(ImageUrl),
@@ -36,7 +36,7 @@ pub enum Image<Gradient, MozImageRect, ImageUrl> {
 
 /// A CSS gradient.
 /// <https://drafts.csswg.org/css-images/#gradients>
-#[derive(Clone, Debug, MallocSizeOf, PartialEq, ToComputedValue, ToShmem)]
+#[derive(Clone, Debug, MallocSizeOf, PartialEq, ToComputedValue, ToResolvedValue, ToShmem)]
 pub struct Gradient<LineDirection, Length, LengthPercentage, Position, Color, Angle> {
     /// Gradients can be linear or radial.
     pub kind: GradientKind<LineDirection, Length, LengthPercentage, Position, Angle>,
@@ -48,7 +48,7 @@ pub struct Gradient<LineDirection, Length, LengthPercentage, Position, Color, An
     pub compat_mode: CompatMode,
 }
 
-#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, ToComputedValue, ToShmem)]
+#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, ToComputedValue, ToResolvedValue, ToShmem)]
 /// Whether we used the modern notation or the compatibility `-webkit`, `-moz` prefixes.
 pub enum CompatMode {
     /// Modern syntax.
@@ -60,7 +60,7 @@ pub enum CompatMode {
 }
 
 /// A gradient kind.
-#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, ToComputedValue, ToShmem)]
+#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, ToComputedValue, ToResolvedValue, ToShmem)]
 pub enum GradientKind<LineDirection, Length, LengthPercentage, Position, Angle> {
     /// A linear gradient.
     Linear(LineDirection),
@@ -73,7 +73,7 @@ pub enum GradientKind<LineDirection, Length, LengthPercentage, Position, Angle>
 }
 
 /// A radial gradient's ending shape.
-#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, ToComputedValue, ToCss, ToShmem)]
+#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, ToComputedValue, ToCss, ToResolvedValue, ToShmem)]
 pub enum EndingShape<Length, LengthPercentage> {
     /// A circular gradient.
     Circle(Circle<Length>),
@@ -82,7 +82,7 @@ pub enum EndingShape<Length, LengthPercentage> {
 }
 
 /// A circle shape.
-#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, ToComputedValue, ToShmem)]
+#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, ToComputedValue, ToResolvedValue, ToShmem)]
 pub enum Circle<Length> {
     /// A circle radius.
     Radius(Length),
@@ -91,7 +91,7 @@ pub enum Circle<Length> {
 }
 
 /// An ellipse shape.
-#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, ToComputedValue, ToCss, ToShmem)]
+#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, ToComputedValue, ToCss, ToResolvedValue, ToShmem)]
 pub enum Ellipse<LengthPercentage> {
     /// An ellipse pair of radii.
     Radii(LengthPercentage, LengthPercentage),
@@ -103,7 +103,7 @@ pub enum Ellipse<LengthPercentage> {
 #[allow(missing_docs)]
 #[cfg_attr(feature = "servo", derive(Deserialize, Serialize))]
 #[derive(
-    Clone, Copy, Debug, Eq, MallocSizeOf, Parse, PartialEq, ToComputedValue, ToCss, ToShmem,
+    Clone, Copy, Debug, Eq, MallocSizeOf, Parse, PartialEq, ToComputedValue, ToCss, ToResolvedValue, ToShmem,
 )]
 pub enum ShapeExtent {
     ClosestSide,
@@ -116,7 +116,7 @@ pub enum ShapeExtent {
 
 /// A gradient item.
 /// <https://drafts.csswg.org/css-images-4/#color-stop-syntax>
-#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, ToComputedValue, ToCss, ToShmem)]
+#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, ToComputedValue, ToCss, ToResolvedValue, ToShmem)]
 pub enum GradientItem<Color, LengthPercentage> {
     /// A color stop.
     ColorStop(ColorStop<Color, LengthPercentage>),
@@ -126,7 +126,7 @@ pub enum GradientItem<Color, LengthPercentage> {
 
 /// A color stop.
 /// <https://drafts.csswg.org/css-images/#typedef-color-stop-list>
-#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, ToComputedValue, ToCss, ToShmem)]
+#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, ToComputedValue, ToCss, ToResolvedValue, ToShmem)]
 pub struct ColorStop<Color, LengthPercentage> {
     /// The color of this stop.
     pub color: Color,
@@ -170,7 +170,7 @@ impl ToCss for PaintWorklet {
 #[allow(missing_docs)]
 #[css(comma, function)]
 #[derive(
-    Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss, ToShmem,
+    Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss, ToResolvedValue, ToShmem,
 )]
 pub struct MozImageRect<NumberOrPercentage, MozImageRectUrl> {
     pub url: MozImageRectUrl,
diff --git a/components/style/values/generics/length.rs b/components/style/values/generics/length.rs
index e805c1b0cd7..1275e739cfe 100644
--- a/components/style/values/generics/length.rs
+++ b/components/style/values/generics/length.rs
@@ -26,6 +26,7 @@ use style_traits::ParseError;
     ToAnimatedZero,
     ToComputedValue,
     ToCss,
+    ToResolvedValue,
     ToShmem,
 )]
 #[repr(C, u8)]
@@ -110,6 +111,7 @@ impl<LengthPercentage: Parse> Parse for LengthPercentageOrAuto<LengthPercentage>
     ToAnimatedZero,
     ToComputedValue,
     ToCss,
+    ToResolvedValue,
     ToShmem,
 )]
 #[repr(C, u8)]
@@ -152,6 +154,7 @@ impl<LengthPercentage> Size<LengthPercentage> {
     ToAnimatedZero,
     ToComputedValue,
     ToCss,
+    ToResolvedValue,
     ToShmem,
 )]
 #[repr(C, u8)]
@@ -188,6 +191,7 @@ impl<LengthPercentage> MaxSize<LengthPercentage> {
     ToAnimatedZero,
     ToComputedValue,
     ToCss,
+    ToResolvedValue,
     ToShmem,
 )]
 #[repr(C, u8)]
diff --git a/components/style/values/generics/mod.rs b/components/style/values/generics/mod.rs
index 44b85931661..e5bb9fa727f 100644
--- a/components/style/values/generics/mod.rs
+++ b/components/style/values/generics/mod.rs
@@ -44,7 +44,7 @@ pub mod url;
 #[allow(missing_docs)]
 #[cfg_attr(feature = "servo", derive(Deserialize, Serialize))]
 #[derive(
-    Clone, Copy, Debug, Eq, MallocSizeOf, Parse, PartialEq, ToComputedValue, ToCss, ToShmem,
+    Clone, Copy, Debug, Eq, MallocSizeOf, Parse, PartialEq, ToComputedValue, ToCss, ToResolvedValue, ToShmem,
 )]
 pub enum SymbolsType {
     Cyclic,
@@ -87,7 +87,7 @@ impl SymbolsType {
 /// Since wherever <counter-style> is used, 'none' is a valid value as
 /// well, we combine them into one type to make code simpler.
 #[cfg_attr(feature = "gecko", derive(MallocSizeOf))]
-#[derive(Clone, Debug, Eq, PartialEq, ToComputedValue, ToCss, ToShmem)]
+#[derive(Clone, Debug, Eq, PartialEq, ToComputedValue, ToCss, ToResolvedValue, ToShmem)]
 pub enum CounterStyleOrNone {
     /// `none`
     None,
@@ -175,6 +175,7 @@ impl SpecifiedValueInfo for CounterStyleOrNone {
     ToAnimatedZero,
     ToComputedValue,
     ToCss,
+    ToResolvedValue,
     ToShmem,
 )]
 #[repr(transparent)]
@@ -213,6 +214,7 @@ impl<T: Zero> Zero for NonNegative<T> {
     ToAnimatedZero,
     ToComputedValue,
     ToCss,
+    ToResolvedValue,
     ToShmem,
 )]
 pub struct GreaterThanOrEqualToOne<T>(pub T);
@@ -231,6 +233,7 @@ pub struct GreaterThanOrEqualToOne<T>(pub T);
     ToAnimatedZero,
     ToComputedValue,
     ToCss,
+    ToResolvedValue,
     ToShmem,
 )]
 #[css(function = "rect", comma)]
diff --git a/components/style/values/generics/position.rs b/components/style/values/generics/position.rs
index 59a86c4b43f..7e43f439793 100644
--- a/components/style/values/generics/position.rs
+++ b/components/style/values/generics/position.rs
@@ -18,6 +18,7 @@
     ToAnimatedValue,
     ToAnimatedZero,
     ToComputedValue,
+    ToResolvedValue,
     ToShmem,
 )]
 #[repr(C)]
@@ -54,6 +55,7 @@ impl<H, V> Position<H, V> {
     ToAnimatedZero,
     ToComputedValue,
     ToCss,
+    ToResolvedValue,
     ToShmem,
 )]
 #[repr(C, u8)]
diff --git a/components/style/values/generics/rect.rs b/components/style/values/generics/rect.rs
index 43f7b34bb06..e4623535146 100644
--- a/components/style/values/generics/rect.rs
+++ b/components/style/values/generics/rect.rs
@@ -22,6 +22,7 @@ use style_traits::{CssWriter, ParseError, ToCss};
     SpecifiedValueInfo,
     ToAnimatedValue,
     ToComputedValue,
+    ToResolvedValue,
     ToShmem,
 )]
 #[repr(C)]
diff --git a/components/style/values/generics/size.rs b/components/style/values/generics/size.rs
index 99cf966de73..fa129bee475 100644
--- a/components/style/values/generics/size.rs
+++ b/components/style/values/generics/size.rs
@@ -24,6 +24,7 @@ use style_traits::{CssWriter, ParseError, ToCss};
     ToAnimatedZero,
     ToAnimatedValue,
     ToComputedValue,
+    ToResolvedValue,
     ToShmem,
 )]
 #[allow(missing_docs)]
diff --git a/components/style/values/generics/svg.rs b/components/style/values/generics/svg.rs
index d385b570291..0cd67dbf10e 100644
--- a/components/style/values/generics/svg.rs
+++ b/components/style/values/generics/svg.rs
@@ -24,6 +24,7 @@ use style_traits::{ParseError, StyleParseErrorKind};
     ToAnimatedValue,
     ToComputedValue,
     ToCss,
+    ToResolvedValue,
     ToShmem,
 )]
 pub struct SVGPaint<ColorType, UrlPaintServer> {
@@ -51,6 +52,7 @@ pub struct SVGPaint<ColorType, UrlPaintServer> {
     ToAnimatedZero,
     ToComputedValue,
     ToCss,
+    ToResolvedValue,
     ToShmem,
 )]
 pub enum SVGPaintKind<ColorType, UrlPaintServer> {
@@ -144,6 +146,7 @@ impl<ColorType: Parse, UrlPaintServer: Parse> Parse for SVGPaint<ColorType, UrlP
     ToAnimatedZero,
     ToComputedValue,
     ToCss,
+    ToResolvedValue,
     ToShmem,
 )]
 pub enum SVGLength<L> {
@@ -165,6 +168,7 @@ pub enum SVGLength<L> {
     ToAnimatedZero,
     ToComputedValue,
     ToCss,
+    ToResolvedValue,
     ToShmem,
 )]
 pub enum SVGStrokeDashArray<L> {
@@ -190,6 +194,7 @@ pub enum SVGStrokeDashArray<L> {
     ToAnimatedZero,
     ToComputedValue,
     ToCss,
+    ToResolvedValue,
     ToShmem,
 )]
 pub enum SVGOpacity<OpacityType> {
diff --git a/components/style/values/generics/text.rs b/components/style/values/generics/text.rs
index 47abc958e65..6324e7dfba8 100644
--- a/components/style/values/generics/text.rs
+++ b/components/style/values/generics/text.rs
@@ -19,6 +19,7 @@ use style_traits::ParseError;
     SpecifiedValueInfo,
     ToComputedValue,
     ToCss,
+    ToResolvedValue,
     ToShmem,
 )]
 pub enum InitialLetter<Number, Integer> {
@@ -92,6 +93,7 @@ fn line_height_moz_block_height_enabled(context: &ParserContext) -> bool {
     ToAnimatedValue,
     ToCss,
     ToShmem,
+    ToResolvedValue,
     Parse,
 )]
 #[repr(C, u8)]
diff --git a/components/style/values/generics/transform.rs b/components/style/values/generics/transform.rs
index 530f2b996ca..bfa59c60fb2 100644
--- a/components/style/values/generics/transform.rs
+++ b/components/style/values/generics/transform.rs
@@ -27,6 +27,7 @@ use style_traits::{CssWriter, ToCss};
     SpecifiedValueInfo,
     ToComputedValue,
     ToCss,
+    ToResolvedValue,
     ToShmem,
 )]
 #[css(comma, function)]
@@ -42,8 +43,18 @@ pub struct Matrix<T> {
 #[allow(missing_docs)]
 #[cfg_attr(rustfmt, rustfmt_skip)]
 #[css(comma, function = "matrix3d")]
-#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo,
-         ToComputedValue, ToCss, ToShmem)]
+#[derive(
+    Clone,
+    Copy,
+    Debug,
+    MallocSizeOf,
+    PartialEq,
+    SpecifiedValueInfo,
+    ToComputedValue,
+    ToCss,
+    ToResolvedValue,
+    ToShmem,
+)]
 pub struct Matrix3D<T> {
     pub m11: T, pub m12: T, pub m13: T, pub m14: T,
     pub m21: T, pub m22: T, pub m23: T, pub m24: T,
@@ -90,6 +101,7 @@ impl<T: Into<f64>> From<Matrix3D<T>> for Transform3D<f64> {
     ToAnimatedZero,
     ToComputedValue,
     ToCss,
+    ToResolvedValue,
     ToShmem,
 )]
 #[repr(C)]
@@ -120,7 +132,7 @@ fn is_same<N: PartialEq>(x: &N, y: &N) -> bool {
 }
 
 #[derive(
-    Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss, ToShmem,
+    Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss, ToResolvedValue, ToShmem,
 )]
 /// A single operation in the list of a `transform` value
 pub enum TransformOperation<Angle, Number, Length, Integer, LengthPercentage>
@@ -227,7 +239,7 @@ where
 }
 
 #[derive(
-    Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss, ToShmem,
+    Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss, ToResolvedValue, ToShmem,
 )]
 /// A value of the `transform` property
 pub struct Transform<T>(#[css(if_empty = "none", iterable)] pub Vec<T>);
@@ -558,6 +570,7 @@ pub fn get_normalized_vector_and_angle<T: Zero>(
     SpecifiedValueInfo,
     ToAnimatedZero,
     ToComputedValue,
+    ToResolvedValue,
     ToShmem,
 )]
 /// A value of the `Rotate` property
@@ -628,6 +641,7 @@ where
     SpecifiedValueInfo,
     ToAnimatedZero,
     ToComputedValue,
+    ToResolvedValue,
     ToShmem,
 )]
 /// A value of the `Scale` property
@@ -677,6 +691,7 @@ impl<Number: ToCss + PartialEq> ToCss for Scale<Number> {
     ToAnimatedZero,
     ToComputedValue,
     ToCss,
+    ToResolvedValue,
     ToShmem,
 )]
 /// A value of the `translate` property
@@ -719,6 +734,7 @@ where
     SpecifiedValueInfo,
     ToComputedValue,
     ToCss,
+    ToResolvedValue,
     ToShmem,
 )]
 pub enum TransformStyle {
diff --git a/components/style/values/generics/ui.rs b/components/style/values/generics/ui.rs
index 294a29d04af..444c9a561d1 100644
--- a/components/style/values/generics/ui.rs
+++ b/components/style/values/generics/ui.rs
@@ -11,7 +11,7 @@ use values::specified::ui::CursorKind;
 /// A generic value for the `cursor` property.
 ///
 /// https://drafts.csswg.org/css-ui/#cursor
-#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToShmem)]
+#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToResolvedValue, ToShmem)]
 pub struct Cursor<Image> {
     /// The parsed images for the cursor.
     pub images: Box<[Image]>,
@@ -44,7 +44,7 @@ impl<Image: ToCss> ToCss for Cursor<Image> {
 }
 
 /// A generic value for item of `image cursors`.
-#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToShmem)]
+#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToResolvedValue, ToShmem)]
 pub struct CursorImage<ImageUrl, Number> {
     /// The url to parse images from.
     pub url: ImageUrl,
@@ -84,6 +84,7 @@ impl<ImageUrl: ToCss, Number: ToCss> ToCss for CursorImage<ImageUrl, Number> {
     ToAnimatedZero,
     ToComputedValue,
     ToCss,
+    ToResolvedValue,
     ToShmem,
 )]
 #[repr(C, u8)]
diff --git a/components/style/values/generics/url.rs b/components/style/values/generics/url.rs
index d86800dbcd4..9dbed038630 100644
--- a/components/style/values/generics/url.rs
+++ b/components/style/values/generics/url.rs
@@ -18,6 +18,7 @@
     ToAnimatedZero,
     ToComputedValue,
     ToCss,
+    ToResolvedValue,
     ToShmem,
 )]
 pub enum UrlOrNone<Url> {
diff --git a/components/style/values/mod.rs b/components/style/values/mod.rs
index 4665257a0c6..b0132d3c341 100644
--- a/components/style/values/mod.rs
+++ b/components/style/values/mod.rs
@@ -28,6 +28,7 @@ pub mod animated;
 pub mod computed;
 pub mod distance;
 pub mod generics;
+pub mod resolved;
 pub mod specified;
 
 /// A CSS float value.
@@ -96,7 +97,7 @@ where
 /// Convenience void type to disable some properties and values through types.
 #[cfg_attr(feature = "servo", derive(Deserialize, MallocSizeOf, Serialize))]
 #[derive(
-    Clone, Copy, Debug, PartialEq, SpecifiedValueInfo, ToAnimatedValue, ToComputedValue, ToCss,
+    Clone, Copy, Debug, PartialEq, SpecifiedValueInfo, ToAnimatedValue, ToComputedValue, ToCss, ToResolvedValue,
 )]
 pub enum Impossible {}
 
@@ -134,6 +135,7 @@ impl Parse for Impossible {
     ToAnimatedZero,
     ToComputedValue,
     ToCss,
+    ToResolvedValue,
     ToShmem,
 )]
 pub enum Either<A, B> {
@@ -154,7 +156,7 @@ impl<A: Debug, B: Debug> Debug for Either<A, B> {
 
 /// <https://drafts.csswg.org/css-values-4/#custom-idents>
 #[derive(
-    Clone, Debug, Eq, Hash, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToShmem,
+    Clone, Debug, Eq, Hash, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToResolvedValue, ToShmem,
 )]
 pub struct CustomIdent(pub Atom);
 
@@ -192,7 +194,7 @@ impl ToCss for CustomIdent {
 }
 
 /// <https://drafts.csswg.org/css-animations/#typedef-keyframes-name>
-#[derive(Clone, Debug, MallocSizeOf, SpecifiedValueInfo, ToComputedValue, ToShmem)]
+#[derive(Clone, Debug, MallocSizeOf, SpecifiedValueInfo, ToComputedValue, ToResolvedValue, ToShmem)]
 pub enum KeyframesName {
     /// <custom-ident>
     Ident(CustomIdent),
diff --git a/components/style/values/specified/align.rs b/components/style/values/specified/align.rs
index e6ba57b6322..20f801d13b2 100644
--- a/components/style/values/specified/align.rs
+++ b/components/style/values/specified/align.rs
@@ -16,7 +16,7 @@ bitflags! {
     /// Constants shared by multiple CSS Box Alignment properties
     ///
     /// These constants match Gecko's `NS_STYLE_ALIGN_*` constants.
-    #[derive(MallocSizeOf, ToComputedValue, ToShmem)]
+    #[derive(MallocSizeOf, ToComputedValue, ToResolvedValue, ToShmem)]
     pub struct AlignFlags: u8 {
         // Enumeration stored in the lower 5 bits:
         /// 'auto'
@@ -134,7 +134,7 @@ pub enum AxisDirection {
 /// Shared value for the `align-content` and `justify-content` properties.
 ///
 /// <https://drafts.csswg.org/css-align/#content-distribution>
-#[derive(Clone, Copy, Debug, Eq, MallocSizeOf, PartialEq, ToComputedValue, ToCss, ToShmem)]
+#[derive(Clone, Copy, Debug, Eq, MallocSizeOf, PartialEq, ToComputedValue, ToCss, ToResolvedValue, ToShmem)]
 #[cfg_attr(feature = "servo", derive(Deserialize, Serialize))]
 pub struct ContentDistribution {
     primary: AlignFlags,
@@ -247,7 +247,7 @@ impl ContentDistribution {
 /// Value for the `align-content` property.
 ///
 /// <https://drafts.csswg.org/css-align/#propdef-align-content>
-#[derive(Clone, Copy, Debug, Eq, MallocSizeOf, PartialEq, ToComputedValue, ToCss, ToShmem)]
+#[derive(Clone, Copy, Debug, Eq, MallocSizeOf, PartialEq, ToComputedValue, ToCss, ToResolvedValue, ToShmem)]
 pub struct AlignContent(pub ContentDistribution);
 
 impl Parse for AlignContent {
@@ -287,7 +287,7 @@ impl From<AlignContent> for u16 {
 /// Value for the `justify-content` property.
 ///
 /// <https://drafts.csswg.org/css-align/#propdef-justify-content>
-#[derive(Clone, Copy, Debug, Eq, MallocSizeOf, PartialEq, ToComputedValue, ToCss, ToShmem)]
+#[derive(Clone, Copy, Debug, Eq, MallocSizeOf, PartialEq, ToComputedValue, ToCss, ToResolvedValue, ToShmem)]
 pub struct JustifyContent(pub ContentDistribution);
 
 impl Parse for JustifyContent {
@@ -325,7 +325,7 @@ impl From<JustifyContent> for u16 {
 }
 
 /// <https://drafts.csswg.org/css-align/#self-alignment>
-#[derive(Clone, Copy, Debug, Eq, MallocSizeOf, PartialEq, ToComputedValue, ToCss, ToShmem)]
+#[derive(Clone, Copy, Debug, Eq, MallocSizeOf, PartialEq, ToComputedValue, ToCss, ToResolvedValue, ToShmem)]
 pub struct SelfAlignment(pub AlignFlags);
 
 impl SelfAlignment {
@@ -385,7 +385,7 @@ impl SelfAlignment {
 /// The specified value of the align-self property.
 ///
 /// <https://drafts.csswg.org/css-align/#propdef-align-self>
-#[derive(Clone, Copy, Debug, Eq, MallocSizeOf, PartialEq, ToComputedValue, ToCss, ToShmem)]
+#[derive(Clone, Copy, Debug, Eq, MallocSizeOf, PartialEq, ToComputedValue, ToCss, ToResolvedValue, ToShmem)]
 pub struct AlignSelf(pub SelfAlignment);
 
 impl Parse for AlignSelf {
@@ -423,7 +423,7 @@ impl From<AlignSelf> for u8 {
 /// The specified value of the justify-self property.
 ///
 /// <https://drafts.csswg.org/css-align/#propdef-justify-self>
-#[derive(Clone, Copy, Debug, Eq, MallocSizeOf, PartialEq, ToComputedValue, ToCss, ToShmem)]
+#[derive(Clone, Copy, Debug, Eq, MallocSizeOf, PartialEq, ToComputedValue, ToCss, ToResolvedValue, ToShmem)]
 pub struct JustifySelf(pub SelfAlignment);
 
 impl Parse for JustifySelf {
@@ -461,7 +461,7 @@ impl From<JustifySelf> for u8 {
 /// Value of the `align-items` property
 ///
 /// <https://drafts.csswg.org/css-align/#propdef-align-items>
-#[derive(Clone, Copy, Debug, Eq, MallocSizeOf, PartialEq, ToComputedValue, ToCss, ToShmem)]
+#[derive(Clone, Copy, Debug, Eq, MallocSizeOf, PartialEq, ToComputedValue, ToCss, ToResolvedValue, ToShmem)]
 pub struct AlignItems(pub AlignFlags);
 
 impl AlignItems {
diff --git a/components/style/values/specified/background.rs b/components/style/values/specified/background.rs
index 6982326b945..f087695db52 100644
--- a/components/style/values/specified/background.rs
+++ b/components/style/values/specified/background.rs
@@ -47,6 +47,7 @@ impl Parse for BackgroundSize {
     SpecifiedValueInfo,
     ToComputedValue,
     ToCss,
+    ToResolvedValue,
     ToShmem,
 )]
 #[allow(missing_docs)]
@@ -63,7 +64,7 @@ pub enum BackgroundRepeatKeyword {
 /// axes.
 ///
 /// https://drafts.csswg.org/css-backgrounds/#the-background-repeat
-#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToShmem)]
+#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToResolvedValue, ToShmem)]
 pub struct BackgroundRepeat(pub BackgroundRepeatKeyword, pub BackgroundRepeatKeyword);
 
 impl BackgroundRepeat {
diff --git a/components/style/values/specified/border.rs b/components/style/values/specified/border.rs
index 415c104a12d..c05217fab0c 100644
--- a/components/style/values/specified/border.rs
+++ b/components/style/values/specified/border.rs
@@ -40,6 +40,7 @@ use style_traits::{CssWriter, ParseError, ToCss};
     SpecifiedValueInfo,
     ToComputedValue,
     ToCss,
+    ToResolvedValue,
     ToShmem,
 )]
 #[repr(u8)]
@@ -264,7 +265,7 @@ pub enum BorderImageRepeatKeyword {
 ///
 /// https://drafts.csswg.org/css-backgrounds/#the-border-image-repeat
 #[derive(
-    Clone, Copy, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToShmem,
+    Clone, Copy, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToResolvedValue, ToShmem,
 )]
 pub struct BorderImageRepeat(pub BorderImageRepeatKeyword, pub BorderImageRepeatKeyword);
 
diff --git a/components/style/values/specified/box.rs b/components/style/values/specified/box.rs
index 6d69c453845..86bb824748c 100644
--- a/components/style/values/specified/box.rs
+++ b/components/style/values/specified/box.rs
@@ -61,6 +61,7 @@ fn moz_box_display_values_enabled(context: &ParserContext) -> bool {
     SpecifiedValueInfo,
     ToComputedValue,
     ToCss,
+    ToResolvedValue,
     ToShmem,
 )]
 #[cfg_attr(feature = "servo", derive(Deserialize, Serialize))]
@@ -326,7 +327,16 @@ impl AnimationIterationCount {
 
 /// A value for the `animation-name` property.
 #[derive(
-    Clone, Debug, Eq, Hash, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToShmem,
+    Clone,
+    Debug,
+    Eq,
+    Hash,
+    MallocSizeOf,
+    PartialEq,
+    SpecifiedValueInfo,
+    ToComputedValue,
+    ToResolvedValue,
+    ToShmem,
 )]
 #[value_info(other_values = "none")]
 pub struct AnimationName(pub Option<KeyframesName>);
@@ -382,6 +392,7 @@ impl Parse for AnimationName {
     SpecifiedValueInfo,
     ToComputedValue,
     ToCss,
+    ToResolvedValue,
     ToShmem,
 )]
 #[repr(u8)]
@@ -406,6 +417,7 @@ pub enum ScrollSnapType {
     SpecifiedValueInfo,
     ToComputedValue,
     ToCss,
+    ToResolvedValue,
     ToShmem,
 )]
 #[repr(u8)]
@@ -419,7 +431,7 @@ pub enum ScrollSnapAlignKeyword {
 /// https://drafts.csswg.org/css-scroll-snap-1/#scroll-snap-align
 #[allow(missing_docs)]
 #[derive(
-    Clone, Copy, Debug, Eq, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToShmem,
+    Clone, Copy, Debug, Eq, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToResolvedValue, ToShmem,
 )]
 #[repr(C)]
 pub struct ScrollSnapAlign {
@@ -477,6 +489,7 @@ impl ToCss for ScrollSnapAlign {
     SpecifiedValueInfo,
     ToComputedValue,
     ToCss,
+    ToResolvedValue,
     ToShmem,
 )]
 #[repr(u8)]
@@ -499,6 +512,7 @@ pub enum OverscrollBehavior {
     SpecifiedValueInfo,
     ToComputedValue,
     ToCss,
+    ToResolvedValue,
     ToShmem,
 )]
 #[repr(u8)]
@@ -520,6 +534,7 @@ pub enum OverflowAnchor {
     SpecifiedValueInfo,
     ToComputedValue,
     ToCss,
+    ToResolvedValue,
     ToShmem,
 )]
 #[repr(u8)]
@@ -529,7 +544,7 @@ pub enum OverflowClipBox {
 }
 
 #[derive(
-    Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss, ToShmem,
+    Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss, ToResolvedValue, ToShmem,
 )]
 /// Provides a rendering hint to the user agent,
 /// stating what kinds of changes the author expects
@@ -562,7 +577,7 @@ impl WillChange {
 
 bitflags! {
     /// The change bits that we care about.
-    #[derive(MallocSizeOf, SpecifiedValueInfo, ToComputedValue, ToShmem)]
+    #[derive(MallocSizeOf, SpecifiedValueInfo, ToComputedValue, ToResolvedValue, ToShmem)]
     #[repr(C)]
     pub struct WillChangeBits: u8 {
         /// Whether the stacking context will change.
@@ -657,8 +672,7 @@ impl Parse for WillChange {
 
 bitflags! {
     /// Values for the `touch-action` property.
-    #[cfg_attr(feature = "gecko", derive(MallocSizeOf))]
-    #[derive(SpecifiedValueInfo, ToComputedValue, ToShmem)]
+    #[derive(MallocSizeOf, SpecifiedValueInfo, ToComputedValue, ToResolvedValue, ToShmem)]
     /// These constants match Gecko's `NS_STYLE_TOUCH_ACTION_*` constants.
     #[value_info(other_values = "auto,none,manipulation,pan-x,pan-y")]
     #[repr(C)]
@@ -731,7 +745,7 @@ impl Parse for TouchAction {
 }
 
 bitflags! {
-    #[derive(MallocSizeOf, SpecifiedValueInfo, ToComputedValue, ToShmem)]
+    #[derive(MallocSizeOf, SpecifiedValueInfo, ToComputedValue, ToResolvedValue, ToShmem)]
     #[value_info(other_values = "none,strict,content,size,layout,paint")]
     #[repr(C)]
     /// Constants for contain: https://drafts.csswg.org/css-contain/#contain-property
@@ -833,7 +847,7 @@ pub type Perspective = GenericPerspective<NonNegativeLength>;
 
 /// A given transition property, that is either `All`, a longhand or shorthand
 /// property, or an unsupported or custom property.
-#[derive(Clone, Debug, Eq, Hash, MallocSizeOf, PartialEq, ToComputedValue, ToShmem)]
+#[derive(Clone, Debug, Eq, Hash, MallocSizeOf, PartialEq, ToComputedValue, ToResolvedValue, ToShmem)]
 pub enum TransitionProperty {
     /// A shorthand.
     Shorthand(ShorthandId),
@@ -1018,6 +1032,7 @@ pub enum Resize {
     SpecifiedValueInfo,
     ToCss,
     ToComputedValue,
+    ToResolvedValue,
     ToShmem,
 )]
 #[repr(u8)]
@@ -1370,6 +1385,7 @@ pub enum Appearance {
     SpecifiedValueInfo,
     ToCss,
     ToComputedValue,
+    ToResolvedValue,
     ToShmem,
 )]
 #[repr(u8)]
@@ -1442,6 +1458,7 @@ impl BreakBetween {
     SpecifiedValueInfo,
     ToCss,
     ToComputedValue,
+    ToResolvedValue,
     ToShmem,
 )]
 #[repr(u8)]
@@ -1464,6 +1481,7 @@ pub enum BreakWithin {
     SpecifiedValueInfo,
     ToCss,
     ToComputedValue,
+    ToResolvedValue,
     ToShmem,
 )]
 #[repr(u8)]
diff --git a/components/style/values/specified/font.rs b/components/style/values/specified/font.rs
index 1e19ebe7a08..809ffe77498 100644
--- a/components/style/values/specified/font.rs
+++ b/components/style/values/specified/font.rs
@@ -995,7 +995,7 @@ bitflags! {
     }
 }
 
-#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToCss, ToShmem)]
+#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToCss, ToResolvedValue, ToShmem)]
 /// Set of variant alternates
 pub enum VariantAlternates {
     /// Enables display of stylistic alternates
@@ -1020,7 +1020,7 @@ pub enum VariantAlternates {
     HistoricalForms,
 }
 
-#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToCss, ToShmem)]
+#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToCss, ToResolvedValue, ToShmem)]
 /// List of Variant Alternates
 pub struct VariantAlternatesList(
     #[css(if_empty = "normal", iterable)] pub Box<[VariantAlternates]>,
@@ -1188,7 +1188,7 @@ macro_rules! impl_variant_east_asian {
         )+
     } => {
         bitflags! {
-            #[derive(MallocSizeOf, ToShmem)]
+            #[derive(MallocSizeOf, ToShmem, ToResolvedValue)]
             /// Vairants for east asian variant
             pub struct VariantEastAsian: u16 {
                 /// None of the features
@@ -1395,7 +1395,7 @@ macro_rules! impl_variant_ligatures {
         )+
     } => {
         bitflags! {
-            #[derive(MallocSizeOf, ToShmem)]
+            #[derive(MallocSizeOf, ToResolvedValue, ToShmem)]
             /// Variants of ligatures
             pub struct VariantLigatures: u16 {
                 /// Specifies that common default features are enabled
@@ -1617,7 +1617,7 @@ macro_rules! impl_variant_numeric {
         )+
     } => {
         bitflags! {
-            #[derive(MallocSizeOf, ToShmem)]
+            #[derive(MallocSizeOf, ToResolvedValue, ToShmem)]
             /// Vairants of numeric values
             pub struct VariantNumeric: u8 {
                 /// None of other variants are enabled.
@@ -1858,7 +1858,7 @@ impl Parse for FontFeatureSettings {
 }
 
 #[derive(
-    Clone, Copy, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToShmem,
+    Clone, Copy, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToResolvedValue, ToShmem,
 )]
 /// Whether user agents are allowed to synthesize bold or oblique font faces
 /// when a font family lacks bold or italic faces
@@ -2158,6 +2158,7 @@ impl Parse for VariationValue<Number> {
     SpecifiedValueInfo,
     ToComputedValue,
     ToCss,
+    ToResolvedValue,
     ToShmem,
 )]
 /// text-zoom. Enable if true, disable if false
@@ -2177,7 +2178,7 @@ impl Parse for XTextZoom {
 }
 
 #[derive(
-    Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss, ToShmem,
+    Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss, ToResolvedValue, ToShmem,
 )]
 /// Internal property that reflects the lang attribute
 pub struct XLang(#[css(skip)] pub Atom);
@@ -2266,7 +2267,7 @@ impl Parse for MozScriptLevel {
 }
 
 #[cfg_attr(feature = "gecko", derive(MallocSizeOf))]
-#[derive(Clone, Copy, Debug, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss, ToShmem)]
+#[derive(Clone, Copy, Debug, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss, ToResolvedValue, ToShmem)]
 /// Specifies the multiplier to be used to adjust font size
 /// due to changes in scriptlevel.
 ///
diff --git a/components/style/values/specified/list.rs b/components/style/values/specified/list.rs
index bf1a17799b2..5a95a9bd7f7 100644
--- a/components/style/values/specified/list.rs
+++ b/components/style/values/specified/list.rs
@@ -16,7 +16,7 @@ use style_traits::{ParseError, StyleParseErrorKind};
 /// Specified and computed `list-style-type` property.
 #[cfg(feature = "gecko")]
 #[derive(
-    Clone, Debug, Eq, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss, ToShmem,
+    Clone, Debug, Eq, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss, ToResolvedValue, ToShmem,
 )]
 pub enum ListStyleType {
     /// <counter-style> | none
@@ -77,7 +77,7 @@ impl Parse for ListStyleType {
 
 /// A quote pair.
 #[derive(
-    Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss, ToShmem,
+    Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss, ToResolvedValue, ToShmem,
 )]
 pub struct QuotePair {
     /// The opening quote.
@@ -89,7 +89,7 @@ pub struct QuotePair {
 
 /// Specified and computed `quotes` property.
 #[derive(
-    Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss, ToShmem,
+    Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss, ToResolvedValue, ToShmem,
 )]
 pub struct Quotes(
     #[css(iterable, if_empty = "none")]
@@ -143,6 +143,7 @@ impl Parse for Quotes {
     SpecifiedValueInfo,
     ToComputedValue,
     ToCss,
+    ToResolvedValue,
     ToShmem,
 )]
 #[repr(u8)]
diff --git a/components/style/values/specified/mod.rs b/components/style/values/specified/mod.rs
index 93f9eca23b6..ea69fd5c577 100644
--- a/components/style/values/specified/mod.rs
+++ b/components/style/values/specified/mod.rs
@@ -709,7 +709,7 @@ impl AllowQuirks {
 ///
 /// `[namespace? `|`]? ident`
 #[derive(
-    Clone, Debug, Eq, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToShmem,
+    Clone, Debug, Eq, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToResolvedValue, ToShmem,
 )]
 #[css(function)]
 pub struct Attr {
diff --git a/components/style/values/specified/motion.rs b/components/style/values/specified/motion.rs
index d9d104bf9c8..7d72796397e 100644
--- a/components/style/values/specified/motion.rs
+++ b/components/style/values/specified/motion.rs
@@ -23,6 +23,7 @@ use style_traits::{ParseError, StyleParseErrorKind};
     ToAnimatedZero,
     ToComputedValue,
     ToCss,
+    ToResolvedValue,
     ToShmem,
 )]
 pub enum OffsetPath {
diff --git a/components/style/values/specified/outline.rs b/components/style/values/specified/outline.rs
index 709c3a94773..b981d8068e7 100644
--- a/components/style/values/specified/outline.rs
+++ b/components/style/values/specified/outline.rs
@@ -22,6 +22,7 @@ use style_traits::ParseError;
     SpecifiedValueInfo,
     ToComputedValue,
     ToCss,
+    ToResolvedValue,
     ToShmem,
 )]
 #[repr(C, u8)]
diff --git a/components/style/values/specified/position.rs b/components/style/values/specified/position.rs
index 43f5b2e4ae2..d3c39b4f582 100644
--- a/components/style/values/specified/position.rs
+++ b/components/style/values/specified/position.rs
@@ -58,6 +58,7 @@ pub enum PositionComponent<S> {
     SpecifiedValueInfo,
     ToComputedValue,
     ToCss,
+    ToResolvedValue,
     ToShmem,
 )]
 #[allow(missing_docs)]
@@ -79,6 +80,7 @@ pub enum X {
     SpecifiedValueInfo,
     ToComputedValue,
     ToCss,
+    ToResolvedValue,
     ToShmem,
 )]
 #[allow(missing_docs)]
@@ -445,6 +447,7 @@ impl ToCss for LegacyPosition {
     SpecifiedValueInfo,
     ToComputedValue,
     ToCss,
+    ToResolvedValue,
     ToShmem,
 )]
 /// Auto-placement algorithm Option
@@ -467,6 +470,7 @@ pub enum AutoFlow {
     SpecifiedValueInfo,
     ToComputedValue,
     ToCss,
+    ToResolvedValue,
     ToShmem,
 )]
 /// Controls how the auto-placement algorithm works
@@ -567,8 +571,7 @@ impl From<GridAutoFlow> for u8 {
     }
 }
 
-#[cfg_attr(feature = "gecko", derive(MallocSizeOf))]
-#[derive(Clone, Debug, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss, ToShmem)]
+#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss, ToResolvedValue, ToShmem)]
 /// https://drafts.csswg.org/css-grid/#named-grid-area
 pub struct TemplateAreas {
     /// `named area` containing for each template area
@@ -675,7 +678,7 @@ impl Parse for TemplateAreas {
 
 /// Arc type for `Arc<TemplateAreas>`
 #[derive(
-    Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss, ToShmem,
+    Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss, ToResolvedValue, ToShmem,
 )]
 pub struct TemplateAreasArc(#[ignore_malloc_size_of = "Arc"] pub Arc<TemplateAreas>);
 
@@ -690,8 +693,7 @@ impl Parse for TemplateAreasArc {
     }
 }
 
-#[cfg_attr(feature = "gecko", derive(MallocSizeOf))]
-#[derive(Clone, Debug, PartialEq, SpecifiedValueInfo, ToShmem)]
+#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToShmem)]
 /// Not associated with any particular grid item, but can
 /// be referenced from the grid-placement properties.
 pub struct NamedArea {
diff --git a/components/style/values/specified/svg.rs b/components/style/values/specified/svg.rs
index c5fe3fe2543..b78b11f2ffa 100644
--- a/components/style/values/specified/svg.rs
+++ b/components/style/values/specified/svg.rs
@@ -129,7 +129,7 @@ const PAINT_ORDER_MASK: u8 = 0b11;
 /// Higher priority values, i.e. the values specified first,
 /// will be painted first (and may be covered by paintings of lower priority)
 #[derive(
-    Clone, Copy, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToShmem,
+    Clone, Copy, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToResolvedValue, ToShmem,
 )]
 pub struct SVGPaintOrder(pub u8);
 
@@ -238,7 +238,7 @@ impl ToCss for SVGPaintOrder {
 /// Specified MozContextProperties value.
 /// Nonstandard (https://developer.mozilla.org/en-US/docs/Web/CSS/-moz-context-properties)
 #[derive(
-    Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss, ToShmem,
+    Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss, ToResolvedValue, ToShmem,
 )]
 pub struct MozContextProperties(pub CustomIdent);
 
diff --git a/components/style/values/specified/svg_path.rs b/components/style/values/specified/svg_path.rs
index 38c743ab756..5509312256a 100644
--- a/components/style/values/specified/svg_path.rs
+++ b/components/style/values/specified/svg_path.rs
@@ -26,6 +26,7 @@ use style_traits::{CssWriter, ParseError, StyleParseErrorKind, ToCss};
     SpecifiedValueInfo,
     ToAnimatedZero,
     ToComputedValue,
+    ToResolvedValue,
     ToShmem,
 )]
 pub struct SVGPathData(Box<[PathCommand]>);
diff --git a/components/style/values/specified/table.rs b/components/style/values/specified/table.rs
index 54680c40d5e..2caace07eb3 100644
--- a/components/style/values/specified/table.rs
+++ b/components/style/values/specified/table.rs
@@ -17,6 +17,7 @@ use style_traits::{ParseError, StyleParseErrorKind};
     SpecifiedValueInfo,
     ToComputedValue,
     ToCss,
+    ToResolvedValue,
     ToShmem,
 )]
 /// span. for `<col span>` pres attr
diff --git a/components/style/values/specified/text.rs b/components/style/values/specified/text.rs
index 75a731d449f..44df9a4c38e 100644
--- a/components/style/values/specified/text.rs
+++ b/components/style/values/specified/text.rs
@@ -228,7 +228,7 @@ impl ToComputedValue for TextOverflow {
 }
 
 bitflags! {
-    #[derive(MallocSizeOf, SpecifiedValueInfo, ToComputedValue, ToShmem)]
+    #[derive(MallocSizeOf, SpecifiedValueInfo, ToComputedValue, ToResolvedValue, ToShmem)]
     #[value_info(other_values = "none,underline,overline,line-through,blink")]
     #[repr(C)]
     /// Specified keyword values for the text-decoration-line property.
@@ -365,6 +365,7 @@ impl TextDecorationLine {
     SpecifiedValueInfo,
     ToComputedValue,
     ToCss,
+    ToResolvedValue,
     ToShmem,
 )]
 #[allow(missing_docs)]
@@ -674,6 +675,7 @@ impl Parse for TextEmphasisStyle {
     SpecifiedValueInfo,
     ToComputedValue,
     ToCss,
+    ToResolvedValue,
     ToShmem,
 )]
 pub enum TextEmphasisHorizontalWritingModeValue {
@@ -695,6 +697,7 @@ pub enum TextEmphasisHorizontalWritingModeValue {
     SpecifiedValueInfo,
     ToComputedValue,
     ToCss,
+    ToResolvedValue,
     ToShmem,
 )]
 pub enum TextEmphasisVerticalWritingModeValue {
@@ -714,6 +717,7 @@ pub enum TextEmphasisVerticalWritingModeValue {
     SpecifiedValueInfo,
     ToComputedValue,
     ToCss,
+    ToResolvedValue,
     ToShmem,
 )]
 pub struct TextEmphasisPosition(
@@ -815,6 +819,7 @@ impl From<TextEmphasisPosition> for u8 {
     SpecifiedValueInfo,
     ToComputedValue,
     ToCss,
+    ToResolvedValue,
     ToShmem,
 )]
 #[allow(missing_docs)]
@@ -843,6 +848,7 @@ pub enum WordBreak {
     SpecifiedValueInfo,
     ToComputedValue,
     ToCss,
+    ToResolvedValue,
     ToShmem,
 )]
 #[allow(missing_docs)]
diff --git a/components/style/values/specified/ui.rs b/components/style/values/specified/ui.rs
index cac8e49309a..52afa0fb256 100644
--- a/components/style/values/specified/ui.rs
+++ b/components/style/values/specified/ui.rs
@@ -57,7 +57,7 @@ impl Parse for CursorImage {
 
 /// Specified value of `-moz-force-broken-image-icon`
 #[derive(
-    Clone, Copy, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToShmem,
+    Clone, Copy, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToResolvedValue, ToShmem,
 )]
 pub struct MozForceBrokenImageIcon(pub bool);
 
@@ -141,6 +141,7 @@ impl Parse for ScrollbarColor {
     SpecifiedValueInfo,
     ToComputedValue,
     ToCss,
+    ToResolvedValue,
     ToShmem,
 )]
 #[repr(u8)]
@@ -169,6 +170,7 @@ pub enum UserSelect {
     SpecifiedValueInfo,
     ToComputedValue,
     ToCss,
+    ToResolvedValue,
     ToShmem,
 )]
 #[repr(u8)]
diff --git a/components/style_derive/lib.rs b/components/style_derive/lib.rs
index 85791c32783..079db00c5a3 100644
--- a/components/style_derive/lib.rs
+++ b/components/style_derive/lib.rs
@@ -25,6 +25,7 @@ mod to_animated_value;
 mod to_animated_zero;
 mod to_computed_value;
 mod to_css;
+mod to_resolved_value;
 
 #[proc_macro_derive(Animate, attributes(animate, animation))]
 pub fn derive_animate(stream: TokenStream) -> TokenStream {
@@ -62,6 +63,12 @@ pub fn derive_to_computed_value(stream: TokenStream) -> TokenStream {
     to_computed_value::derive(input).into()
 }
 
+#[proc_macro_derive(ToResolvedValue, attributes(resolve))]
+pub fn derive_to_resolved_value(stream: TokenStream) -> TokenStream {
+    let input = syn::parse(stream).unwrap();
+    to_resolved_value::derive(input).into()
+}
+
 #[proc_macro_derive(ToCss, attributes(css))]
 pub fn derive_to_css(stream: TokenStream) -> TokenStream {
     let input = syn::parse(stream).unwrap();

From 5fd4e17020a31fd0222d1b5e64bbaa7ad1424319 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Emilio=20Cobos=20=C3=81lvarez?= <emilio@crisal.io>
Date: Wed, 10 Apr 2019 12:10:40 +0000
Subject: [PATCH 48/59] style: Use ToResolvedValue for computed style
 serialization.

Differential Revision: https://phabricator.services.mozilla.com/D26784
---
 components/style/properties/properties.mako.rs | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/components/style/properties/properties.mako.rs b/components/style/properties/properties.mako.rs
index bb9a9ef64c9..5f44a259641 100644
--- a/components/style/properties/properties.mako.rs
+++ b/components/style/properties/properties.mako.rs
@@ -39,7 +39,7 @@ use style_traits::{SpecifiedValueInfo, StyleParseErrorKind, ToCss};
 use to_shmem::impl_trivial_to_shmem;
 use crate::stylesheets::{CssRuleType, Origin, UrlExtraData};
 use crate::values::generics::text::LineHeight;
-use crate::values::computed;
+use crate::values::{computed, resolved};
 use crate::values::computed::NonNegativeLength;
 use crate::values::serialize_atom_name;
 use crate::rule_tree::StrongRuleNode;
@@ -2812,19 +2812,19 @@ impl ComputedValues {
     where
         W: Write,
     {
+        use crate::values::resolved::ToResolvedValue;
+
+        let context = resolved::Context {
+            style: self,
+        };
+
         // TODO(emilio): Is it worth to merge branches here just like
         // PropertyDeclaration::to_css does?
-        //
-        // We'd need to get a concept of ~resolved value, which may not be worth
-        // it.
         match property_id {
             % for prop in data.longhands:
             LonghandId::${prop.camel_case} => {
                 let value = self.clone_${prop.ident}();
-                % if prop.predefined_type == "Color":
-                let value = self.resolve_color(value);
-                % endif
-                value.to_css(dest)
+                value.to_resolved_value(&context).to_css(dest)
             }
             % endfor
         }

From 0f57b7b83307862ce91351262638db9ee59c5aa8 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Emilio=20Cobos=20=C3=81lvarez?= <emilio@crisal.io>
Date: Wed, 10 Apr 2019 12:10:49 +0000
Subject: [PATCH 49/59] style: Fix ToResolvedValue implementation for
 caret-color, and serialize some color properties with Servo.

Differential Revision: https://phabricator.services.mozilla.com/D26785
---
 components/style/values/generics/color.rs |  1 -
 components/style/values/resolved/color.rs | 45 +++++++++++++++++++++++
 components/style/values/resolved/mod.rs   | 22 ++---------
 3 files changed, 48 insertions(+), 20 deletions(-)
 create mode 100644 components/style/values/resolved/color.rs

diff --git a/components/style/values/generics/color.rs b/components/style/values/generics/color.rs
index 0f67f4eb7ca..5aa287baadf 100644
--- a/components/style/values/generics/color.rs
+++ b/components/style/values/generics/color.rs
@@ -99,7 +99,6 @@ impl<RGBA> From<RGBA> for Color<RGBA> {
     ToAnimatedZero,
     ToComputedValue,
     ToCss,
-    ToResolvedValue,
     ToShmem,
 )]
 #[repr(C, u8)]
diff --git a/components/style/values/resolved/color.rs b/components/style/values/resolved/color.rs
new file mode 100644
index 00000000000..1b845c58e9f
--- /dev/null
+++ b/components/style/values/resolved/color.rs
@@ -0,0 +1,45 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+//! Resolved color values.
+
+use super::{Context, ToResolvedValue};
+
+use crate::values::computed;
+use crate::values::generics::color as generics;
+
+impl ToResolvedValue for computed::Color {
+    // A resolved color value is an rgba color, with currentcolor resolved.
+    type ResolvedValue = cssparser::RGBA;
+
+    #[inline]
+    fn to_resolved_value(self, context: &Context) -> Self::ResolvedValue {
+        context.style.resolve_color(self)
+    }
+
+    #[inline]
+    fn from_resolved_value(resolved: Self::ResolvedValue) -> Self {
+        generics::Color::Numeric(resolved)
+    }
+}
+
+impl ToResolvedValue for computed::ColorOrAuto {
+    // A resolved caret-color value is an rgba color, with auto resolving to
+    // currentcolor.
+    type ResolvedValue = cssparser::RGBA;
+
+    #[inline]
+    fn to_resolved_value(self, context: &Context) -> Self::ResolvedValue {
+        let color = match self {
+            generics::ColorOrAuto::Color(color) => color,
+            generics::ColorOrAuto::Auto => generics::Color::CurrentColor,
+        };
+        color.to_resolved_value(context)
+    }
+
+    #[inline]
+    fn from_resolved_value(resolved: Self::ResolvedValue) -> Self {
+        generics::ColorOrAuto::Color(computed::Color::from_resolved_value(resolved))
+    }
+}
diff --git a/components/style/values/resolved/mod.rs b/components/style/values/resolved/mod.rs
index 8d5aa221157..33609cbd89d 100644
--- a/components/style/values/resolved/mod.rs
+++ b/components/style/values/resolved/mod.rs
@@ -8,6 +8,9 @@
 use cssparser;
 use smallvec::SmallVec;
 use crate::properties::ComputedValues;
+
+mod color;
+
 use crate::values::computed;
 
 /// Information needed to resolve a given value.
@@ -187,22 +190,3 @@ where
         Vec::from_resolved_value(Vec::from(resolved)).into_boxed_slice()
     }
 }
-
-
-/// A resolved color value is an rgba color, with currentcolor resolved.
-pub type Color = cssparser::RGBA;
-
-impl ToResolvedValue for computed::Color {
-    type ResolvedValue = Color;
-
-    #[inline]
-    fn to_resolved_value(self, context: &Context) -> Self::ResolvedValue {
-        context.style.resolve_color(self)
-    }
-
-    #[inline]
-    fn from_resolved_value(resolved: Self::ResolvedValue) -> Self {
-        use crate::values::generics::color::Color as GenericColor;
-        GenericColor::Numeric(resolved)
-    }
-}

From 0a8407376766fe7eb6250faf604e3be6c5d4e8b6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Emilio=20Cobos=20=C3=81lvarez?= <emilio@crisal.io>
Date: Wed, 10 Apr 2019 16:00:03 +0000
Subject: [PATCH 50/59] style: Use rust lengths for row-gap / column-gap.

Differential Revision: https://phabricator.services.mozilla.com/D26915
---
 components/style/gecko/values.rs              | 61 +------------------
 components/style/properties/gecko.mako.rs     |  1 -
 components/style/properties/helpers.mako.rs   |  4 +-
 .../properties/longhands/position.mako.rs     |  4 +-
 components/style/values/computed/length.rs    |  7 ++-
 components/style/values/generics/length.rs    | 35 +++++++++++
 components/style/values/mod.rs                |  1 -
 components/style/values/specified/length.rs   |  7 ++-
 8 files changed, 48 insertions(+), 72 deletions(-)

diff --git a/components/style/gecko/values.rs b/components/style/gecko/values.rs
index 946fa437d64..8b05e1520b4 100644
--- a/components/style/gecko/values.rs
+++ b/components/style/gecko/values.rs
@@ -18,7 +18,7 @@ use crate::values::generics::gecko::ScrollSnapPoint;
 use crate::values::generics::grid::{TrackBreadth, TrackKeyword};
 use crate::values::generics::length::LengthPercentageOrAuto;
 use crate::values::generics::{CounterStyleOrNone, NonNegative};
-use crate::values::{Auto, Either, None_, Normal};
+use crate::values::Either;
 use crate::{Atom, Zero};
 use app_units::Au;
 use cssparser::RGBA;
@@ -44,23 +44,6 @@ impl nsStyleCoord {
     }
 }
 
-impl<A: GeckoStyleCoordConvertible, B: GeckoStyleCoordConvertible> GeckoStyleCoordConvertible
-    for Either<A, B>
-{
-    fn to_gecko_style_coord<T: CoordDataMut>(&self, coord: &mut T) {
-        match *self {
-            Either::First(ref v) => v.to_gecko_style_coord(coord),
-            Either::Second(ref v) => v.to_gecko_style_coord(coord),
-        }
-    }
-
-    fn from_gecko_style_coord<T: CoordData>(coord: &T) -> Option<Self> {
-        A::from_gecko_style_coord(coord)
-            .map(Either::First)
-            .or_else(|| B::from_gecko_style_coord(coord).map(Either::Second))
-    }
-}
-
 impl<Inner> GeckoStyleCoordConvertible for NonNegative<Inner>
 where
     Inner: GeckoStyleCoordConvertible,
@@ -265,48 +248,6 @@ impl GeckoStyleCoordConvertible for Angle {
     }
 }
 
-impl GeckoStyleCoordConvertible for Auto {
-    fn to_gecko_style_coord<T: CoordDataMut>(&self, coord: &mut T) {
-        coord.set_value(CoordDataValue::Auto)
-    }
-
-    fn from_gecko_style_coord<T: CoordData>(coord: &T) -> Option<Self> {
-        if let CoordDataValue::Auto = coord.as_value() {
-            Some(Auto)
-        } else {
-            None
-        }
-    }
-}
-
-impl GeckoStyleCoordConvertible for None_ {
-    fn to_gecko_style_coord<T: CoordDataMut>(&self, coord: &mut T) {
-        coord.set_value(CoordDataValue::None)
-    }
-
-    fn from_gecko_style_coord<T: CoordData>(coord: &T) -> Option<Self> {
-        if let CoordDataValue::None = coord.as_value() {
-            Some(None_)
-        } else {
-            None
-        }
-    }
-}
-
-impl GeckoStyleCoordConvertible for Normal {
-    fn to_gecko_style_coord<T: CoordDataMut>(&self, coord: &mut T) {
-        coord.set_value(CoordDataValue::Normal)
-    }
-
-    fn from_gecko_style_coord<T: CoordData>(coord: &T) -> Option<Self> {
-        if let CoordDataValue::Normal = coord.as_value() {
-            Some(Normal)
-        } else {
-            None
-        }
-    }
-}
-
 impl GeckoStyleCoordConvertible for ScrollSnapPoint<LengthPercentage> {
     fn to_gecko_style_coord<T: CoordDataMut>(&self, coord: &mut T) {
         match self.repeated() {
diff --git a/components/style/properties/gecko.mako.rs b/components/style/properties/gecko.mako.rs
index 837a295fb60..81e1ee4307d 100644
--- a/components/style/properties/gecko.mako.rs
+++ b/components/style/properties/gecko.mako.rs
@@ -1190,7 +1190,6 @@ impl Clone for ${style_struct.gecko_struct_name} {
 
     # Types used with predefined_type()-defined properties that we can auto-generate.
     predefined_types = {
-        "length::NonNegativeLengthPercentageOrNormal": impl_style_coord,
         "MozScriptMinSize": impl_absolute_length,
         "SVGLength": impl_svg_length,
         "SVGOpacity": impl_svg_opacity,
diff --git a/components/style/properties/helpers.mako.rs b/components/style/properties/helpers.mako.rs
index c441268975d..8310d537f36 100644
--- a/components/style/properties/helpers.mako.rs
+++ b/components/style/properties/helpers.mako.rs
@@ -105,7 +105,7 @@
             #[allow(unused_imports)]
             use crate::values::{computed, specified};
             #[allow(unused_imports)]
-            use crate::values::{Auto, Either, None_, Normal};
+            use crate::values::{Auto, Either, None_};
             ${caller.body()}
         }
 
@@ -292,7 +292,7 @@
         #[allow(unused_imports)]
         use crate::properties::{UnparsedValue, ShorthandId};
         #[allow(unused_imports)]
-        use crate::values::{Auto, Either, None_, Normal};
+        use crate::values::{Auto, Either, None_};
         #[allow(unused_imports)]
         use crate::error_reporting::ParseErrorReporter;
         #[allow(unused_imports)]
diff --git a/components/style/properties/longhands/position.mako.rs b/components/style/properties/longhands/position.mako.rs
index 725f0862a99..096349f4b1c 100644
--- a/components/style/properties/longhands/position.mako.rs
+++ b/components/style/properties/longhands/position.mako.rs
@@ -372,7 +372,7 @@ ${helpers.predefined_type(
 ${helpers.predefined_type(
     "column-gap",
     "length::NonNegativeLengthPercentageOrNormal",
-    "Either::Second(Normal)",
+    "computed::length::NonNegativeLengthPercentageOrNormal::normal()",
     alias="grid-column-gap" if product == "gecko" else "",
     extra_prefixes="moz",
     servo_pref="layout.columns.enabled",
@@ -385,7 +385,7 @@ ${helpers.predefined_type(
 ${helpers.predefined_type(
     "row-gap",
     "length::NonNegativeLengthPercentageOrNormal",
-    "Either::Second(Normal)",
+    "computed::length::NonNegativeLengthPercentageOrNormal::normal()",
     alias="grid-row-gap",
     products="gecko",
     spec="https://drafts.csswg.org/css-align-3/#propdef-row-gap",
diff --git a/components/style/values/computed/length.rs b/components/style/values/computed/length.rs
index 92215541e8a..1e1fedd41bf 100644
--- a/components/style/values/computed/length.rs
+++ b/components/style/values/computed/length.rs
@@ -10,12 +10,13 @@ use crate::values::computed::NonNegativeNumber;
 use crate::values::distance::{ComputeSquaredDistance, SquaredDistance};
 use crate::values::generics::length as generics;
 use crate::values::generics::length::{
-    GenericLengthOrNumber, MaxSize as GenericMaxSize, Size as GenericSize,
+    GenericLengthPercentageOrNormal, GenericLengthOrNumber,
+    GenericMaxSize, GenericSize,
 };
 use crate::values::generics::NonNegative;
 use crate::values::specified::length::ViewportPercentageLength;
 use crate::values::specified::length::{AbsoluteLength, FontBaseSize, FontRelativeLength};
-use crate::values::{specified, CSSFloat, Either, Normal};
+use crate::values::{specified, CSSFloat};
 use crate::Zero;
 use app_units::Au;
 use ordered_float::NotNan;
@@ -782,7 +783,7 @@ impl From<NonNegativeLength> for Au {
 }
 
 /// Either a computed NonNegativeLengthPercentage or the `normal` keyword.
-pub type NonNegativeLengthPercentageOrNormal = Either<NonNegativeLengthPercentage, Normal>;
+pub type NonNegativeLengthPercentageOrNormal = GenericLengthPercentageOrNormal<NonNegativeLengthPercentage>;
 
 /// Either a non-negative `<length>` or a `<number>`.
 pub type NonNegativeLengthOrNumber = GenericLengthOrNumber<NonNegativeLength, NonNegativeNumber>;
diff --git a/components/style/values/generics/length.rs b/components/style/values/generics/length.rs
index 1275e739cfe..1665f144778 100644
--- a/components/style/values/generics/length.rs
+++ b/components/style/values/generics/length.rs
@@ -219,3 +219,38 @@ impl<L, N: Zero> Zero for LengthOrNumber<L, N> {
         }
     }
 }
+
+/// A generic `<length-percentage>` | normal` value.
+#[derive(
+    Animate,
+    Clone,
+    ComputeSquaredDistance,
+    Copy,
+    Debug,
+    MallocSizeOf,
+    Parse,
+    PartialEq,
+    SpecifiedValueInfo,
+    ToAnimatedValue,
+    ToAnimatedZero,
+    ToComputedValue,
+    ToCss,
+    ToResolvedValue,
+    ToShmem,
+)]
+#[repr(C, u8)]
+#[allow(missing_docs)]
+pub enum GenericLengthPercentageOrNormal<LengthPercent> {
+    LengthPercentage(LengthPercent),
+    Normal,
+}
+
+pub use self::GenericLengthPercentageOrNormal as LengthPercentageOrNormal;
+
+impl<LengthPercent> LengthPercentageOrNormal<LengthPercent> {
+    /// Returns the normal value.
+    #[inline]
+    pub fn normal() -> Self {
+        LengthPercentageOrNormal::Normal
+    }
+}
diff --git a/components/style/values/mod.rs b/components/style/values/mod.rs
index b0132d3c341..89f0de816f2 100644
--- a/components/style/values/mod.rs
+++ b/components/style/values/mod.rs
@@ -39,7 +39,6 @@ pub type CSSInteger = i32;
 
 define_keyword_type!(None_, "none");
 define_keyword_type!(Auto, "auto");
-define_keyword_type!(Normal, "normal");
 
 /// Serialize an identifier which is represented as an atom.
 #[cfg(feature = "gecko")]
diff --git a/components/style/values/specified/length.rs b/components/style/values/specified/length.rs
index 8d29fe53a00..a6beef91ee5 100644
--- a/components/style/values/specified/length.rs
+++ b/components/style/values/specified/length.rs
@@ -13,12 +13,13 @@ use crate::properties::computed_value_flags::ComputedValueFlags;
 use crate::values::computed::{self, CSSPixelLength, Context};
 use crate::values::generics::length as generics;
 use crate::values::generics::length::{
-    GenericLengthOrNumber, MaxSize as GenericMaxSize, Size as GenericSize,
+    GenericLengthPercentageOrNormal, GenericLengthOrNumber,
+    GenericMaxSize, GenericSize,
 };
 use crate::values::generics::NonNegative;
 use crate::values::specified::calc::CalcNode;
 use crate::values::specified::NonNegativeNumber;
-use crate::values::{CSSFloat, Either, Normal};
+use crate::values::CSSFloat;
 use crate::Zero;
 use app_units::Au;
 use cssparser::{Parser, Token};
@@ -957,7 +958,7 @@ impl NonNegativeLengthPercentageOrAuto {
 pub type NonNegativeLengthPercentage = NonNegative<LengthPercentage>;
 
 /// Either a NonNegativeLengthPercentage or the `normal` keyword.
-pub type NonNegativeLengthPercentageOrNormal = Either<NonNegativeLengthPercentage, Normal>;
+pub type NonNegativeLengthPercentageOrNormal = GenericLengthPercentageOrNormal<NonNegativeLengthPercentage>;
 
 impl From<NoCalcLength> for NonNegativeLengthPercentage {
     #[inline]

From 2f457ed144bf8960f54671c2e27705e59610e0dd Mon Sep 17 00:00:00 2001
From: Hiroyuki Ikezoe <hikezoe@mozilla.com>
Date: Thu, 11 Apr 2019 06:19:13 +0000
Subject: [PATCH 51/59] style: Rename ScrollSnapType to ScrollSnapStrictness.

The scroll snap strictness is defined in the new spec [1], and the structure
is the exactly same as the old scroll snap type structure.

[1] https://drafts.csswg.org/css-scroll-snap-1/#snap-strictness

Differential Revision: https://phabricator.services.mozilla.com/D21621
---
 components/style/properties/data.py               | 2 +-
 components/style/properties/longhands/box.mako.rs | 4 ++--
 components/style/values/computed/box.rs           | 2 +-
 components/style/values/computed/mod.rs           | 2 +-
 components/style/values/specified/box.rs          | 3 ++-
 components/style/values/specified/mod.rs          | 2 +-
 6 files changed, 8 insertions(+), 7 deletions(-)

diff --git a/components/style/properties/data.py b/components/style/properties/data.py
index 52cdcf15d22..b6d42d8ecd5 100644
--- a/components/style/properties/data.py
+++ b/components/style/properties/data.py
@@ -341,7 +341,7 @@ class Longhand(object):
                 "SVGOpacity",
                 "SVGPaintOrder",
                 "ScrollSnapAlign",
-                "ScrollSnapType",
+                "ScrollSnapStrictness",
                 "TextAlign",
                 "TextDecorationLine",
                 "TextEmphasisPosition",
diff --git a/components/style/properties/longhands/box.mako.rs b/components/style/properties/longhands/box.mako.rs
index dcfcb343040..9d18753f53f 100644
--- a/components/style/properties/longhands/box.mako.rs
+++ b/components/style/properties/longhands/box.mako.rs
@@ -430,8 +430,8 @@ ${helpers.predefined_type(
 % for axis in ["x", "y"]:
     ${helpers.predefined_type(
         "scroll-snap-type-" + axis,
-        "ScrollSnapType",
-        "computed::ScrollSnapType::None",
+        "ScrollSnapStrictness",
+        "computed::ScrollSnapStrictness::None",
         products="gecko",
         needs_context=False,
         gecko_pref="layout.css.scroll-snap.enabled",
diff --git a/components/style/values/computed/box.rs b/components/style/values/computed/box.rs
index 1fb92bec13a..fc7df203d54 100644
--- a/components/style/values/computed/box.rs
+++ b/components/style/values/computed/box.rs
@@ -15,7 +15,7 @@ pub use crate::values::specified::box_::{AnimationName, Appearance, BreakBetween
 pub use crate::values::specified::box_::{Clear as SpecifiedClear, Float as SpecifiedFloat};
 pub use crate::values::specified::box_::{Contain, Display, Overflow};
 pub use crate::values::specified::box_::{OverflowAnchor, OverflowClipBox};
-pub use crate::values::specified::box_::{OverscrollBehavior, ScrollSnapAlign, ScrollSnapType};
+pub use crate::values::specified::box_::{OverscrollBehavior, ScrollSnapAlign, ScrollSnapStrictness};
 pub use crate::values::specified::box_::{TouchAction, TransitionProperty, WillChange};
 
 /// A computed value for the `vertical-align` property.
diff --git a/components/style/values/computed/mod.rs b/components/style/values/computed/mod.rs
index f01661cbc9c..74df937904d 100644
--- a/components/style/values/computed/mod.rs
+++ b/components/style/values/computed/mod.rs
@@ -42,7 +42,7 @@ pub use self::box_::{AnimationIterationCount, AnimationName, Contain};
 pub use self::box_::{Appearance, BreakBetween, BreakWithin, Clear, Float};
 pub use self::box_::{Display, Overflow, OverflowAnchor, TransitionProperty};
 pub use self::box_::{OverflowClipBox, OverscrollBehavior, Perspective, Resize};
-pub use self::box_::{ScrollSnapAlign, ScrollSnapType, TouchAction, VerticalAlign, WillChange};
+pub use self::box_::{ScrollSnapAlign, ScrollSnapStrictness, TouchAction, VerticalAlign, WillChange};
 pub use self::color::{Color, ColorOrAuto, ColorPropertyValue};
 pub use self::column::ColumnCount;
 pub use self::counters::{Content, ContentItem, CounterIncrement, CounterSetOrReset};
diff --git a/components/style/values/specified/box.rs b/components/style/values/specified/box.rs
index 86bb824748c..29e2272f6b1 100644
--- a/components/style/values/specified/box.rs
+++ b/components/style/values/specified/box.rs
@@ -379,6 +379,7 @@ impl Parse for AnimationName {
     }
 }
 
+/// https://drafts.csswg.org/css-scroll-snap-1/#snap-strictness
 #[allow(missing_docs)]
 #[cfg_attr(feature = "servo", derive(Deserialize, Serialize))]
 #[derive(
@@ -396,7 +397,7 @@ impl Parse for AnimationName {
     ToShmem,
 )]
 #[repr(u8)]
-pub enum ScrollSnapType {
+pub enum ScrollSnapStrictness {
     None,
     Mandatory,
     Proximity,
diff --git a/components/style/values/specified/mod.rs b/components/style/values/specified/mod.rs
index ea69fd5c577..09675d01fe2 100644
--- a/components/style/values/specified/mod.rs
+++ b/components/style/values/specified/mod.rs
@@ -40,7 +40,7 @@ pub use self::box_::{AnimationIterationCount, AnimationName, Contain, Display};
 pub use self::box_::{Appearance, BreakBetween, BreakWithin};
 pub use self::box_::{Clear, Float, Overflow, OverflowAnchor};
 pub use self::box_::{OverflowClipBox, OverscrollBehavior, Perspective, Resize};
-pub use self::box_::{ScrollSnapAlign, ScrollSnapType};
+pub use self::box_::{ScrollSnapAlign, ScrollSnapStrictness};
 pub use self::box_::{TouchAction, TransitionProperty, VerticalAlign, WillChange};
 pub use self::color::{Color, ColorOrAuto, ColorPropertyValue};
 pub use self::column::ColumnCount;

From 21481e315e5d82d33dab906980379fbd398d1ba9 Mon Sep 17 00:00:00 2001
From: Hiroyuki Ikezoe <hikezoe@mozilla.com>
Date: Thu, 11 Apr 2019 06:19:31 +0000
Subject: [PATCH 52/59] style: Switch to the new scroll-snap-type syntax for
 the old scroll snap implementation and drop the scroll-snap-type-{x,y}
 longhands.

Now scroll-snap-type is a longhand property.

Differential Revision: https://phabricator.services.mozilla.com/D21622
---
 components/style/properties/data.py           |  2 +
 .../style/properties/longhands/box.mako.rs    | 21 ++---
 .../style/properties/shorthands/box.mako.rs   | 30 ------
 components/style/values/computed/box.rs       |  4 +-
 components/style/values/computed/mod.rs       |  3 +-
 components/style/values/specified/box.rs      | 94 ++++++++++++++++++-
 components/style/values/specified/mod.rs      |  2 +-
 7 files changed, 109 insertions(+), 47 deletions(-)

diff --git a/components/style/properties/data.py b/components/style/properties/data.py
index b6d42d8ecd5..407cc5fcdb0 100644
--- a/components/style/properties/data.py
+++ b/components/style/properties/data.py
@@ -341,7 +341,9 @@ class Longhand(object):
                 "SVGOpacity",
                 "SVGPaintOrder",
                 "ScrollSnapAlign",
+                "ScrollSnapAxis",
                 "ScrollSnapStrictness",
+                "ScrollSnapType",
                 "TextAlign",
                 "TextDecorationLine",
                 "TextEmphasisPosition",
diff --git a/components/style/properties/longhands/box.mako.rs b/components/style/properties/longhands/box.mako.rs
index 9d18753f53f..87d4f59af31 100644
--- a/components/style/properties/longhands/box.mako.rs
+++ b/components/style/properties/longhands/box.mako.rs
@@ -427,18 +427,15 @@ ${helpers.predefined_type(
     animation_value_type="discrete",
 )}
 
-% for axis in ["x", "y"]:
-    ${helpers.predefined_type(
-        "scroll-snap-type-" + axis,
-        "ScrollSnapStrictness",
-        "computed::ScrollSnapStrictness::None",
-        products="gecko",
-        needs_context=False,
-        gecko_pref="layout.css.scroll-snap.enabled",
-        spec="Nonstandard (https://developer.mozilla.org/en-US/docs/Web/CSS/scroll-snap-type-x)",
-        animation_value_type="discrete",
-    )}
-% endfor
+${helpers.predefined_type(
+    "scroll-snap-type",
+    "ScrollSnapType",
+    "computed::ScrollSnapType::none()",
+    products="gecko",
+    gecko_pref="layout.css.scroll-snap.enabled",
+    spec="https://drafts.csswg.org/css-scroll-snap-1/#scroll-snap-type",
+    animation_value_type="discrete",
+)}
 
 % for axis in ["x", "y"]:
     ${helpers.predefined_type(
diff --git a/components/style/properties/shorthands/box.mako.rs b/components/style/properties/shorthands/box.mako.rs
index 0acb72b6bb9..5c03dba8529 100644
--- a/components/style/properties/shorthands/box.mako.rs
+++ b/components/style/properties/shorthands/box.mako.rs
@@ -303,36 +303,6 @@ macro_rules! try_parse_one {
     }
 </%helpers:shorthand>
 
-<%helpers:shorthand name="scroll-snap-type" products="gecko"
-                    gecko_pref="layout.css.scroll-snap.enabled"
-                    sub_properties="scroll-snap-type-x scroll-snap-type-y"
-                    spec="https://drafts.csswg.org/css-scroll-snap/#propdef-scroll-snap-type">
-    use crate::properties::longhands::scroll_snap_type_x;
-
-    pub fn parse_value<'i, 't>(
-        context: &ParserContext,
-        input: &mut Parser<'i, 't>,
-    ) -> Result<Longhands, ParseError<'i>> {
-        let result = scroll_snap_type_x::parse(context, input)?;
-        Ok(expanded! {
-            scroll_snap_type_x: result,
-            scroll_snap_type_y: result,
-        })
-    }
-
-    impl<'a> ToCss for LonghandsToSerialize<'a>  {
-        // Serializes into the single keyword value if both scroll-snap-type-x and scroll-snap-type-y are same.
-        // Otherwise into an empty string. This is done to match Gecko's behaviour.
-        fn to_css<W>(&self, dest: &mut CssWriter<W>) -> fmt::Result where W: fmt::Write {
-            if self.scroll_snap_type_x == self.scroll_snap_type_y {
-                self.scroll_snap_type_x.to_css(dest)
-            } else {
-                Ok(())
-            }
-        }
-    }
-</%helpers:shorthand>
-
 ${helpers.two_properties_shorthand(
     "overscroll-behavior",
     "overscroll-behavior-x",
diff --git a/components/style/values/computed/box.rs b/components/style/values/computed/box.rs
index fc7df203d54..c7a3ba7e36e 100644
--- a/components/style/values/computed/box.rs
+++ b/components/style/values/computed/box.rs
@@ -14,8 +14,8 @@ use crate::values::specified::box_ as specified;
 pub use crate::values::specified::box_::{AnimationName, Appearance, BreakBetween, BreakWithin};
 pub use crate::values::specified::box_::{Clear as SpecifiedClear, Float as SpecifiedFloat};
 pub use crate::values::specified::box_::{Contain, Display, Overflow};
-pub use crate::values::specified::box_::{OverflowAnchor, OverflowClipBox};
-pub use crate::values::specified::box_::{OverscrollBehavior, ScrollSnapAlign, ScrollSnapStrictness};
+pub use crate::values::specified::box_::{OverflowAnchor, OverflowClipBox, OverscrollBehavior};
+pub use crate::values::specified::box_::{ScrollSnapAlign, ScrollSnapAxis, ScrollSnapStrictness, ScrollSnapType};
 pub use crate::values::specified::box_::{TouchAction, TransitionProperty, WillChange};
 
 /// A computed value for the `vertical-align` property.
diff --git a/components/style/values/computed/mod.rs b/components/style/values/computed/mod.rs
index 74df937904d..72de7f2238e 100644
--- a/components/style/values/computed/mod.rs
+++ b/components/style/values/computed/mod.rs
@@ -42,7 +42,8 @@ pub use self::box_::{AnimationIterationCount, AnimationName, Contain};
 pub use self::box_::{Appearance, BreakBetween, BreakWithin, Clear, Float};
 pub use self::box_::{Display, Overflow, OverflowAnchor, TransitionProperty};
 pub use self::box_::{OverflowClipBox, OverscrollBehavior, Perspective, Resize};
-pub use self::box_::{ScrollSnapAlign, ScrollSnapStrictness, TouchAction, VerticalAlign, WillChange};
+pub use self::box_::{ScrollSnapAlign, ScrollSnapAxis, ScrollSnapStrictness, ScrollSnapType};
+pub use self::box_::{TouchAction, VerticalAlign, WillChange};
 pub use self::color::{Color, ColorOrAuto, ColorPropertyValue};
 pub use self::column::ColumnCount;
 pub use self::counters::{Content, ContentItem, CounterIncrement, CounterSetOrReset};
diff --git a/components/style/values/specified/box.rs b/components/style/values/specified/box.rs
index 29e2272f6b1..c003bf966bb 100644
--- a/components/style/values/specified/box.rs
+++ b/components/style/values/specified/box.rs
@@ -379,6 +379,32 @@ impl Parse for AnimationName {
     }
 }
 
+/// https://drafts.csswg.org/css-scroll-snap-1/#snap-axis
+#[allow(missing_docs)]
+#[cfg_attr(feature = "servo", derive(Deserialize, Serialize))]
+#[derive(
+    Clone,
+    Copy,
+    Debug,
+    Eq,
+    MallocSizeOf,
+    Parse,
+    PartialEq,
+    SpecifiedValueInfo,
+    ToComputedValue,
+    ToCss,
+    ToResolvedValue,
+    ToShmem,
+)]
+#[repr(u8)]
+pub enum ScrollSnapAxis {
+    X,
+    Y,
+    Block,
+    Inline,
+    Both,
+}
+
 /// https://drafts.csswg.org/css-scroll-snap-1/#snap-strictness
 #[allow(missing_docs)]
 #[cfg_attr(feature = "servo", derive(Deserialize, Serialize))]
@@ -398,11 +424,77 @@ impl Parse for AnimationName {
 )]
 #[repr(u8)]
 pub enum ScrollSnapStrictness {
-    None,
+    #[css(skip)]
+    None, // Used to represent scroll-snap-type: none.  It's not parsed.
     Mandatory,
     Proximity,
 }
 
+/// https://drafts.csswg.org/css-scroll-snap-1/#scroll-snap-type
+#[allow(missing_docs)]
+#[cfg_attr(feature = "servo", derive(Deserialize, Serialize))]
+#[derive(
+    Clone,
+    Copy,
+    Debug,
+    Eq,
+    MallocSizeOf,
+    PartialEq,
+    SpecifiedValueInfo,
+    ToComputedValue,
+    ToResolvedValue,
+    ToShmem,
+)]
+#[repr(C)]
+pub struct ScrollSnapType {
+    axis: ScrollSnapAxis,
+    strictness: ScrollSnapStrictness,
+}
+
+impl ScrollSnapType {
+    /// Returns `none`.
+    #[inline]
+    pub fn none() -> Self {
+        Self {
+            axis: ScrollSnapAxis::Both,
+            strictness: ScrollSnapStrictness::None,
+        }
+    }
+}
+
+impl Parse for ScrollSnapType {
+    /// none | [ x | y | block | inline | both ] [ mandatory | proximity ]?
+    fn parse<'i, 't>(
+        _context: &ParserContext,
+        input: &mut Parser<'i, 't>,
+    ) -> Result<Self, ParseError<'i>> {
+        if input.try(|input| input.expect_ident_matching("none")).is_ok() {
+            return Ok(ScrollSnapType::none());
+        }
+
+        let axis = ScrollSnapAxis::parse(input)?;
+        let strictness = input.try(ScrollSnapStrictness::parse).unwrap_or(ScrollSnapStrictness::Proximity);
+        Ok(Self { axis, strictness })
+    }
+}
+
+impl ToCss for ScrollSnapType {
+    fn to_css<W>(&self, dest: &mut CssWriter<W>) -> fmt::Result
+    where
+        W: Write,
+    {
+        if self.strictness == ScrollSnapStrictness::None {
+            return dest.write_str("none");
+        }
+        self.axis.to_css(dest)?;
+        if self.strictness != ScrollSnapStrictness::Proximity {
+            dest.write_str(" ")?;
+            self.strictness.to_css(dest)?;
+        }
+        Ok(())
+    }
+}
+
 /// Specified value of scroll-snap-align keyword value.
 #[allow(missing_docs)]
 #[derive(
diff --git a/components/style/values/specified/mod.rs b/components/style/values/specified/mod.rs
index 09675d01fe2..5c9e413cb09 100644
--- a/components/style/values/specified/mod.rs
+++ b/components/style/values/specified/mod.rs
@@ -40,7 +40,7 @@ pub use self::box_::{AnimationIterationCount, AnimationName, Contain, Display};
 pub use self::box_::{Appearance, BreakBetween, BreakWithin};
 pub use self::box_::{Clear, Float, Overflow, OverflowAnchor};
 pub use self::box_::{OverflowClipBox, OverscrollBehavior, Perspective, Resize};
-pub use self::box_::{ScrollSnapAlign, ScrollSnapStrictness};
+pub use self::box_::{ScrollSnapAlign, ScrollSnapAxis, ScrollSnapStrictness, ScrollSnapType};
 pub use self::box_::{TouchAction, TransitionProperty, VerticalAlign, WillChange};
 pub use self::color::{Color, ColorOrAuto, ColorPropertyValue};
 pub use self::column::ColumnCount;

From cf7f64c9dcc511e93d9504054ebad193a5f83ff7 Mon Sep 17 00:00:00 2001
From: Hiroyuki Ikezoe <hikezoe@mozilla.com>
Date: Thu, 11 Apr 2019 06:22:01 +0000
Subject: [PATCH 53/59] style: Enable the new scroll snap and disable the old
 scroll snap on nightly.

Differential Revision: https://phabricator.services.mozilla.com/D22804
---
 components/style/properties/longhands/box.mako.rs | 1 -
 1 file changed, 1 deletion(-)

diff --git a/components/style/properties/longhands/box.mako.rs b/components/style/properties/longhands/box.mako.rs
index 87d4f59af31..397393ed3d8 100644
--- a/components/style/properties/longhands/box.mako.rs
+++ b/components/style/properties/longhands/box.mako.rs
@@ -432,7 +432,6 @@ ${helpers.predefined_type(
     "ScrollSnapType",
     "computed::ScrollSnapType::none()",
     products="gecko",
-    gecko_pref="layout.css.scroll-snap.enabled",
     spec="https://drafts.csswg.org/css-scroll-snap-1/#scroll-snap-type",
     animation_value_type="discrete",
 )}

From 7c4f9bbf494387c2046d614f5d8769b7ce7eed67 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Emilio=20Cobos=20=C3=81lvarez?= <emilio@crisal.io>
Date: Thu, 11 Apr 2019 15:21:17 +0000
Subject: [PATCH 54/59] style: Make the list-item increment not visible from
 the computed style.

This is per https://drafts.csswg.org/css-lists/#declaring-a-list-item.

I intentionally kept <li value> defined using attribute mapping, I think that's
saner than special-casing it in layout.

Differential Revision: https://phabricator.services.mozilla.com/D24935
---
 components/style/style_adjuster.rs | 39 ------------------------------
 1 file changed, 39 deletions(-)

diff --git a/components/style/style_adjuster.rs b/components/style/style_adjuster.rs
index e0efe35c86f..63af60e16ab 100644
--- a/components/style/style_adjuster.rs
+++ b/components/style/style_adjuster.rs
@@ -723,44 +723,6 @@ impl<'a, 'b: 'a> StyleAdjuster<'a, 'b> {
         }
     }
 
-    /// For HTML elements with 'display:list-item' we add a default 'counter-increment:list-item'
-    /// unless 'counter-increment' already has a value for 'list-item'.
-    ///
-    /// https://drafts.csswg.org/css-lists-3/#declaring-a-list-item
-    #[cfg(feature = "gecko")]
-    fn adjust_for_list_item(&mut self) {
-        use crate::properties::longhands::counter_increment::computed_value::T as ComputedIncrement;
-        use crate::values::generics::counters::CounterPair;
-        use crate::values::specified::list::MozListReversed;
-        use crate::values::CustomIdent;
-
-        if self.style.get_box().clone_display() != Display::ListItem {
-            return;
-        }
-        if self.style.pseudo.is_some() {
-            return;
-        }
-
-        let increments = self.style.get_counters().clone_counter_increment();
-        if increments.iter().any(|i| i.name.0 == atom!("list-item")) {
-            return;
-        }
-
-        let reversed = self.style.get_list().clone__moz_list_reversed() == MozListReversed::True;
-        let increment = if reversed { -1 } else { 1 };
-        let list_increment = CounterPair {
-            name: CustomIdent(atom!("list-item")),
-            value: increment,
-        };
-        let increments = increments
-            .iter()
-            .cloned()
-            .chain(std::iter::once(list_increment));
-        self.style
-            .mutate_counters()
-            .set_counter_increment(ComputedIncrement::new(increments.collect()));
-    }
-
     /// Adjusts the style to account for various fixups that don't fit naturally
     /// into the cascade.
     ///
@@ -825,7 +787,6 @@ impl<'a, 'b: 'a> StyleAdjuster<'a, 'b> {
         #[cfg(feature = "gecko")]
         {
             self.adjust_for_appearance(element);
-            self.adjust_for_list_item();
         }
         self.set_bits();
     }

From 8c004c08580287172585169807ed36933ad674f8 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Emilio=20Cobos=20=C3=81lvarez?= <emilio@crisal.io>
Date: Thu, 11 Apr 2019 22:12:41 +0200
Subject: [PATCH 55/59] style: Reformat recent changes.

---
 components/selectors/parser.rs                | 13 ++-
 components/style/error_reporting.rs           | 10 +-
 components/style/font_metrics.rs              |  6 +-
 components/style/gecko/wrapper.rs             |  6 +-
 components/style/gecko_string_cache/mod.rs    |  6 +-
 components/style/stylesheets/rule_parser.rs   |  2 +-
 components/style/values/computed/angle.rs     | 13 ++-
 components/style/values/computed/box.rs       |  4 +-
 components/style/values/computed/font.rs      | 50 ++++++----
 components/style/values/computed/length.rs    |  6 +-
 components/style/values/computed/mod.rs       |  4 +-
 components/style/values/generics/border.rs    | 12 ++-
 components/style/values/generics/color.rs     |  2 +-
 components/style/values/generics/counters.rs  | 10 +-
 components/style/values/generics/grid.rs      | 15 ++-
 components/style/values/generics/image.rs     | 42 +++++++--
 components/style/values/generics/mod.rs       | 12 ++-
 components/style/values/generics/text.rs      | 11 +--
 components/style/values/generics/transform.rs | 20 +++-
 components/style/values/generics/ui.rs        | 22 ++++-
 components/style/values/mod.rs                | 25 ++++-
 components/style/values/resolved/mod.rs       |  6 +-
 components/style/values/specified/align.rs    | 91 +++++++++++++++++--
 .../style/values/specified/background.rs      | 11 ++-
 components/style/values/specified/border.rs   | 10 +-
 components/style/values/specified/box.rs      | 70 +++++++-------
 components/style/values/specified/color.rs    |  4 +-
 components/style/values/specified/font.rs     | 48 ++++++++--
 components/style/values/specified/length.rs   |  6 +-
 components/style/values/specified/list.rs     | 31 ++++++-
 components/style/values/specified/mod.rs      | 10 +-
 components/style/values/specified/position.rs | 22 ++++-
 components/style/values/specified/svg.rs      | 20 +++-
 components/style/values/specified/text.rs     |  4 +-
 components/style/values/specified/ui.rs       | 10 +-
 components/style_derive/to_animated_value.rs  | 26 +++---
 components/style_derive/to_computed_value.rs  | 43 ++++-----
 components/style_derive/to_resolved_value.rs  | 32 +++----
 components/to_shmem/lib.rs                    | 38 +++++---
 components/to_shmem_derive/to_shmem.rs        | 10 +-
 40 files changed, 571 insertions(+), 212 deletions(-)

diff --git a/components/selectors/parser.rs b/components/selectors/parser.rs
index 765c0d842c1..0515eaca193 100644
--- a/components/selectors/parser.rs
+++ b/components/selectors/parser.rs
@@ -223,7 +223,9 @@ pub trait Parser<'i> {
 
 #[derive(Clone, Debug, Eq, PartialEq, ToShmem)]
 #[shmem(no_bounds)]
-pub struct SelectorList<Impl: SelectorImpl>(#[shmem(field_bound)] pub SmallVec<[Selector<Impl>; 1]>);
+pub struct SelectorList<Impl: SelectorImpl>(
+    #[shmem(field_bound)] pub SmallVec<[Selector<Impl>; 1]>,
+);
 
 impl<Impl: SelectorImpl> SelectorList<Impl> {
     /// Parse a comma-separated list of Selectors.
@@ -510,7 +512,9 @@ pub fn namespace_empty_string<Impl: SelectorImpl>() -> Impl::NamespaceUrl {
 /// handle it in to_css to make it invisible to serialization.
 #[derive(Clone, Eq, PartialEq, ToShmem)]
 #[shmem(no_bounds)]
-pub struct Selector<Impl: SelectorImpl>(#[shmem(field_bound)] ThinArc<SpecificityAndFlags, Component<Impl>>);
+pub struct Selector<Impl: SelectorImpl>(
+    #[shmem(field_bound)] ThinArc<SpecificityAndFlags, Component<Impl>>,
+);
 
 impl<Impl: SelectorImpl> Selector<Impl> {
     #[inline]
@@ -834,7 +838,10 @@ pub enum Component<Impl: SelectorImpl> {
     ExplicitAnyNamespace,
     ExplicitNoNamespace,
     DefaultNamespace(#[shmem(field_bound)] Impl::NamespaceUrl),
-    Namespace(#[shmem(field_bound)] Impl::NamespacePrefix, #[shmem(field_bound)] Impl::NamespaceUrl),
+    Namespace(
+        #[shmem(field_bound)] Impl::NamespacePrefix,
+        #[shmem(field_bound)] Impl::NamespaceUrl,
+    ),
 
     ExplicitUniversalType,
     LocalName(LocalName<Impl>),
diff --git a/components/style/error_reporting.rs b/components/style/error_reporting.rs
index 9d54f62e318..04677c26041 100644
--- a/components/style/error_reporting.rs
+++ b/components/style/error_reporting.rs
@@ -6,18 +6,22 @@
 
 #![deny(missing_docs)]
 
+use crate::selector_parser::SelectorImpl;
 use crate::stylesheets::UrlExtraData;
 use cssparser::{BasicParseErrorKind, ParseErrorKind, SourceLocation, Token};
+use selectors::SelectorList;
 use std::fmt;
 use style_traits::ParseError;
-use crate::selector_parser::{SelectorImpl};
-use selectors::SelectorList;
 
 /// Errors that can be encountered while parsing CSS.
 #[derive(Debug)]
 pub enum ContextualParseError<'a> {
     /// A property declaration was not recognized.
-    UnsupportedPropertyDeclaration(&'a str, ParseError<'a>, Option<&'a SelectorList<SelectorImpl>>),
+    UnsupportedPropertyDeclaration(
+        &'a str,
+        ParseError<'a>,
+        Option<&'a SelectorList<SelectorImpl>>,
+    ),
     /// A font face descriptor was not recognized.
     UnsupportedFontFaceDescriptor(&'a str, ParseError<'a>),
     /// A font feature values descriptor was not recognized.
diff --git a/components/style/font_metrics.rs b/components/style/font_metrics.rs
index ab2468e5439..a45ebc297d9 100644
--- a/components/style/font_metrics.rs
+++ b/components/style/font_metrics.rs
@@ -43,7 +43,11 @@ pub trait FontMetricsProvider {
     }
 
     /// Get default size of a given language and generic family.
-    fn get_size(&self, font_name: &Atom, font_family: crate::values::computed::font::GenericFontFamily) -> Au;
+    fn get_size(
+        &self,
+        font_name: &Atom,
+        font_family: crate::values::computed::font::GenericFontFamily,
+    ) -> Au;
 
     /// Construct from a shared style context
     fn create_from(context: &SharedStyleContext) -> Self
diff --git a/components/style/gecko/wrapper.rs b/components/style/gecko/wrapper.rs
index a1f06a679d9..0fa354fb139 100644
--- a/components/style/gecko/wrapper.rs
+++ b/components/style/gecko/wrapper.rs
@@ -1108,9 +1108,9 @@ impl structs::FontSizePrefs {
             GenericFontFamily::Monospace => self.mDefaultMonospaceSize,
             GenericFontFamily::Cursive => self.mDefaultCursiveSize,
             GenericFontFamily::Fantasy => self.mDefaultFantasySize,
-            GenericFontFamily::MozEmoji => {
-                unreachable!("Should never get here, since this doesn't (yet) appear on font family")
-            },
+            GenericFontFamily::MozEmoji => unreachable!(
+                "Should never get here, since this doesn't (yet) appear on font family"
+            ),
         })
     }
 }
diff --git a/components/style/gecko_string_cache/mod.rs b/components/style/gecko_string_cache/mod.rs
index f4c875cb7ad..d71d192166a 100644
--- a/components/style/gecko_string_cache/mod.rs
+++ b/components/style/gecko_string_cache/mod.rs
@@ -126,7 +126,11 @@ impl Borrow<WeakAtom> for Atom {
 
 impl ToShmem for Atom {
     fn to_shmem(&self, _builder: &mut SharedMemoryBuilder) -> ManuallyDrop<Self> {
-        assert!(self.is_static(), "ToShmem failed for Atom: must be a static atom: {}", self);
+        assert!(
+            self.is_static(),
+            "ToShmem failed for Atom: must be a static atom: {}",
+            self
+        );
 
         ManuallyDrop::new(Atom(self.0))
     }
diff --git a/components/style/stylesheets/rule_parser.rs b/components/style/stylesheets/rule_parser.rs
index 33190c578b4..a3ec24174ed 100644
--- a/components/style/stylesheets/rule_parser.rs
+++ b/components/style/stylesheets/rule_parser.rs
@@ -9,7 +9,7 @@ use crate::error_reporting::ContextualParseError;
 use crate::font_face::parse_font_face_block;
 use crate::media_queries::MediaList;
 use crate::parser::{Parse, ParserContext};
-use crate::properties::{parse_property_declaration_list};
+use crate::properties::parse_property_declaration_list;
 use crate::selector_parser::{SelectorImpl, SelectorParser};
 use crate::shared_lock::{Locked, SharedRwLock};
 use crate::str::starts_with_ignore_ascii_case;
diff --git a/components/style/values/computed/angle.rs b/components/style/values/computed/angle.rs
index 1ce1a7fd34d..cdbc0006941 100644
--- a/components/style/values/computed/angle.rs
+++ b/components/style/values/computed/angle.rs
@@ -14,7 +14,18 @@ use style_traits::{CssWriter, ToCss};
 
 /// A computed angle in degrees.
 #[cfg_attr(feature = "servo", derive(Deserialize, Serialize))]
-#[derive(Add, Animate, Clone, Copy, Debug, MallocSizeOf, PartialEq, PartialOrd, ToAnimatedZero, ToResolvedValue)]
+#[derive(
+    Add,
+    Animate,
+    Clone,
+    Copy,
+    Debug,
+    MallocSizeOf,
+    PartialEq,
+    PartialOrd,
+    ToAnimatedZero,
+    ToResolvedValue,
+)]
 pub struct Angle(CSSFloat);
 
 impl ToCss for Angle {
diff --git a/components/style/values/computed/box.rs b/components/style/values/computed/box.rs
index c7a3ba7e36e..4cd16b1cd9e 100644
--- a/components/style/values/computed/box.rs
+++ b/components/style/values/computed/box.rs
@@ -15,7 +15,9 @@ pub use crate::values::specified::box_::{AnimationName, Appearance, BreakBetween
 pub use crate::values::specified::box_::{Clear as SpecifiedClear, Float as SpecifiedFloat};
 pub use crate::values::specified::box_::{Contain, Display, Overflow};
 pub use crate::values::specified::box_::{OverflowAnchor, OverflowClipBox, OverscrollBehavior};
-pub use crate::values::specified::box_::{ScrollSnapAlign, ScrollSnapAxis, ScrollSnapStrictness, ScrollSnapType};
+pub use crate::values::specified::box_::{
+    ScrollSnapAlign, ScrollSnapAxis, ScrollSnapStrictness, ScrollSnapType,
+};
 pub use crate::values::specified::box_::{TouchAction, TransitionProperty, WillChange};
 
 /// A computed value for the `vertical-align` property.
diff --git a/components/style/values/computed/font.rs b/components/style/values/computed/font.rs
index 152bbcc0d4b..001b8444a30 100644
--- a/components/style/values/computed/font.rs
+++ b/components/style/values/computed/font.rs
@@ -40,7 +40,9 @@ pub use crate::values::specified::font::{XLang, XTextZoom};
 /// https://drafts.csswg.org/css-fonts-4/#propdef-font-weight
 ///
 /// This is effectively just a `Number`.
-#[derive(Clone, ComputeSquaredDistance, Copy, Debug, MallocSizeOf, PartialEq, ToCss, ToResolvedValue)]
+#[derive(
+    Clone, ComputeSquaredDistance, Copy, Debug, MallocSizeOf, PartialEq, ToCss, ToResolvedValue,
+)]
 #[cfg_attr(feature = "servo", derive(Deserialize, Serialize))]
 pub struct FontWeight(pub Number);
 
@@ -190,7 +192,9 @@ impl FontFamily {
     /// Get default font family as `serif` which is a generic font-family
     pub fn serif() -> Self {
         FontFamily {
-            families: FontFamilyList::new(Box::new([SingleFontFamily::Generic(GenericFontFamily::Serif)])),
+            families: FontFamilyList::new(Box::new([SingleFontFamily::Generic(
+                GenericFontFamily::Serif,
+            )])),
             is_system_font: false,
         }
     }
@@ -427,8 +431,10 @@ impl PartialEq for FontFamilyList {
             return false;
         }
         for (a, b) in self_list.mNames.iter().zip(other_list.mNames.iter()) {
-            if a.mSyntax != b.mSyntax || a.mName.mRawPtr != b.mName.mRawPtr ||
-                a.mGeneric != b.mGeneric {
+            if a.mSyntax != b.mSyntax ||
+                a.mName.mRawPtr != b.mName.mRawPtr ||
+                a.mGeneric != b.mGeneric
+            {
                 return false;
             }
         }
@@ -459,19 +465,15 @@ impl FontFamilyList {
 
         for family in families.iter() {
             match *family {
-                SingleFontFamily::FamilyName(ref f) => {
-                    unsafe {
-                        bindings::Gecko_nsTArray_FontFamilyName_AppendNamed(
-                            names,
-                            f.name.as_ptr(),
-                            f.syntax,
-                        );
-                    }
+                SingleFontFamily::FamilyName(ref f) => unsafe {
+                    bindings::Gecko_nsTArray_FontFamilyName_AppendNamed(
+                        names,
+                        f.name.as_ptr(),
+                        f.syntax,
+                    );
                 },
-                SingleFontFamily::Generic(family) => {
-                    unsafe {
-                        bindings::Gecko_nsTArray_FontFamilyName_AppendGeneric(names, family);
-                    }
+                SingleFontFamily::Generic(family) => unsafe {
+                    bindings::Gecko_nsTArray_FontFamilyName_AppendGeneric(names, family);
                 },
             }
         }
@@ -547,7 +549,17 @@ impl<'a> Iterator for FontFamilyNameIter<'a> {
 }
 
 /// Preserve the readability of text when font fallback occurs
-#[derive(Animate, Clone, ComputeSquaredDistance, Copy, Debug, MallocSizeOf, PartialEq, ToCss, ToResolvedValue)]
+#[derive(
+    Animate,
+    Clone,
+    ComputeSquaredDistance,
+    Copy,
+    Debug,
+    MallocSizeOf,
+    PartialEq,
+    ToCss,
+    ToResolvedValue,
+)]
 pub enum FontSizeAdjust {
     #[animation(error)]
     /// None variant
@@ -831,7 +843,9 @@ impl ToCss for FontStyle {
 /// A value for the font-stretch property per:
 ///
 /// https://drafts.csswg.org/css-fonts-4/#propdef-font-stretch
-#[derive(Clone, ComputeSquaredDistance, Copy, Debug, MallocSizeOf, PartialEq, ToCss, ToResolvedValue)]
+#[derive(
+    Clone, ComputeSquaredDistance, Copy, Debug, MallocSizeOf, PartialEq, ToCss, ToResolvedValue,
+)]
 #[cfg_attr(feature = "servo", derive(Deserialize, Serialize))]
 pub struct FontStretch(pub NonNegativePercentage);
 
diff --git a/components/style/values/computed/length.rs b/components/style/values/computed/length.rs
index 1e1fedd41bf..f43befbbaf0 100644
--- a/components/style/values/computed/length.rs
+++ b/components/style/values/computed/length.rs
@@ -10,8 +10,7 @@ use crate::values::computed::NonNegativeNumber;
 use crate::values::distance::{ComputeSquaredDistance, SquaredDistance};
 use crate::values::generics::length as generics;
 use crate::values::generics::length::{
-    GenericLengthPercentageOrNormal, GenericLengthOrNumber,
-    GenericMaxSize, GenericSize,
+    GenericLengthOrNumber, GenericLengthPercentageOrNormal, GenericMaxSize, GenericSize,
 };
 use crate::values::generics::NonNegative;
 use crate::values::specified::length::ViewportPercentageLength;
@@ -783,7 +782,8 @@ impl From<NonNegativeLength> for Au {
 }
 
 /// Either a computed NonNegativeLengthPercentage or the `normal` keyword.
-pub type NonNegativeLengthPercentageOrNormal = GenericLengthPercentageOrNormal<NonNegativeLengthPercentage>;
+pub type NonNegativeLengthPercentageOrNormal =
+    GenericLengthPercentageOrNormal<NonNegativeLengthPercentage>;
 
 /// Either a non-negative `<length>` or a `<number>`.
 pub type NonNegativeLengthOrNumber = GenericLengthOrNumber<NonNegativeLength, NonNegativeNumber>;
diff --git a/components/style/values/computed/mod.rs b/components/style/values/computed/mod.rs
index 72de7f2238e..3b32f8fecd7 100644
--- a/components/style/values/computed/mod.rs
+++ b/components/style/values/computed/mod.rs
@@ -535,7 +535,9 @@ impl From<GreaterThanOrEqualToOneNumber> for CSSFloat {
 }
 
 #[allow(missing_docs)]
-#[derive(Clone, ComputeSquaredDistance, Copy, Debug, MallocSizeOf, PartialEq, ToCss, ToResolvedValue)]
+#[derive(
+    Clone, ComputeSquaredDistance, Copy, Debug, MallocSizeOf, PartialEq, ToCss, ToResolvedValue,
+)]
 #[repr(C, u8)]
 pub enum NumberOrPercentage {
     Percentage(Percentage),
diff --git a/components/style/values/generics/border.rs b/components/style/values/generics/border.rs
index fb6f1537662..ec0ab1c4b07 100644
--- a/components/style/values/generics/border.rs
+++ b/components/style/values/generics/border.rs
@@ -75,7 +75,11 @@ pub use self::GenericBorderImageSlice as BorderImageSlice;
     ToShmem,
 )]
 #[repr(C)]
-pub struct GenericBorderCornerRadius<L>(#[css(field_bound)] #[shmem(field_bound)] pub Size2D<L>);
+pub struct GenericBorderCornerRadius<L>(
+    #[css(field_bound)]
+    #[shmem(field_bound)]
+    pub Size2D<L>,
+);
 
 pub use self::GenericBorderCornerRadius as BorderCornerRadius;
 
@@ -114,7 +118,11 @@ impl<L: Zero> Zero for BorderCornerRadius<L> {
     ToShmem,
 )]
 #[repr(transparent)]
-pub struct BorderSpacing<L>(#[css(field_bound)] #[shmem(field_bound)] pub Size2D<L>);
+pub struct BorderSpacing<L>(
+    #[css(field_bound)]
+    #[shmem(field_bound)]
+    pub Size2D<L>,
+);
 
 impl<L> BorderSpacing<L> {
     /// Trivially create a `BorderCornerRadius`.
diff --git a/components/style/values/generics/color.rs b/components/style/values/generics/color.rs
index 5aa287baadf..b4f2e7445ea 100644
--- a/components/style/values/generics/color.rs
+++ b/components/style/values/generics/color.rs
@@ -40,7 +40,7 @@ pub enum GenericColor<RGBA> {
         color: RGBA,
         /// The ratios of mixing between numeric and currentcolor.
         ratios: ComplexColorRatios,
-    }
+    },
 }
 
 pub use self::GenericColor as Color;
diff --git a/components/style/values/generics/counters.rs b/components/style/values/generics/counters.rs
index 9da5b9140d9..17ac687a670 100644
--- a/components/style/values/generics/counters.rs
+++ b/components/style/values/generics/counters.rs
@@ -15,7 +15,15 @@ use std::ops::Deref;
 
 /// A name / value pair for counters.
 #[derive(
-    Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss, ToResolvedValue, ToShmem,
+    Clone,
+    Debug,
+    MallocSizeOf,
+    PartialEq,
+    SpecifiedValueInfo,
+    ToComputedValue,
+    ToCss,
+    ToResolvedValue,
+    ToShmem,
 )]
 pub struct CounterPair<Integer> {
     /// The name of the counter.
diff --git a/components/style/values/generics/grid.rs b/components/style/values/generics/grid.rs
index 17af16e5167..393e570f066 100644
--- a/components/style/values/generics/grid.rs
+++ b/components/style/values/generics/grid.rs
@@ -379,7 +379,9 @@ where
 /// The initial argument of the `repeat` function.
 ///
 /// <https://drafts.csswg.org/css-grid/#typedef-track-repeat>
-#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, ToComputedValue, ToCss, ToResolvedValue, ToShmem)]
+#[derive(
+    Clone, Copy, Debug, MallocSizeOf, PartialEq, ToComputedValue, ToCss, ToResolvedValue, ToShmem,
+)]
 pub enum RepeatCount<Integer> {
     /// A positive integer. This is allowed only for `<track-repeat>` and `<fixed-repeat>`
     Number(Integer),
@@ -414,7 +416,16 @@ impl Parse for RepeatCount<specified::Integer> {
 ///
 /// It can also hold `repeat()` function parameters, which expands into the respective
 /// values in its computed form.
-#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToResolvedValue, ToShmem)]
+#[derive(
+    Clone,
+    Debug,
+    MallocSizeOf,
+    PartialEq,
+    SpecifiedValueInfo,
+    ToComputedValue,
+    ToResolvedValue,
+    ToShmem,
+)]
 #[css(function = "repeat")]
 pub struct TrackRepeat<L, I> {
     /// The number of times for the value to be repeated (could also be `auto-fit` or `auto-fill`)
diff --git a/components/style/values/generics/image.rs b/components/style/values/generics/image.rs
index 59fc260f93a..a7fa6da9337 100644
--- a/components/style/values/generics/image.rs
+++ b/components/style/values/generics/image.rs
@@ -16,7 +16,9 @@ use style_traits::{CssWriter, ToCss};
 /// An [image].
 ///
 /// [image]: https://drafts.csswg.org/css-images/#image-values
-#[derive(Clone, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToResolvedValue, ToShmem)]
+#[derive(
+    Clone, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToResolvedValue, ToShmem,
+)]
 pub enum Image<Gradient, MozImageRect, ImageUrl> {
     /// A `<url()>` image.
     Url(ImageUrl),
@@ -73,7 +75,9 @@ pub enum GradientKind<LineDirection, Length, LengthPercentage, Position, Angle>
 }
 
 /// A radial gradient's ending shape.
-#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, ToComputedValue, ToCss, ToResolvedValue, ToShmem)]
+#[derive(
+    Clone, Copy, Debug, MallocSizeOf, PartialEq, ToComputedValue, ToCss, ToResolvedValue, ToShmem,
+)]
 pub enum EndingShape<Length, LengthPercentage> {
     /// A circular gradient.
     Circle(Circle<Length>),
@@ -91,7 +95,9 @@ pub enum Circle<Length> {
 }
 
 /// An ellipse shape.
-#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, ToComputedValue, ToCss, ToResolvedValue, ToShmem)]
+#[derive(
+    Clone, Copy, Debug, MallocSizeOf, PartialEq, ToComputedValue, ToCss, ToResolvedValue, ToShmem,
+)]
 pub enum Ellipse<LengthPercentage> {
     /// An ellipse pair of radii.
     Radii(LengthPercentage, LengthPercentage),
@@ -103,7 +109,17 @@ pub enum Ellipse<LengthPercentage> {
 #[allow(missing_docs)]
 #[cfg_attr(feature = "servo", derive(Deserialize, Serialize))]
 #[derive(
-    Clone, Copy, Debug, Eq, MallocSizeOf, Parse, PartialEq, ToComputedValue, ToCss, ToResolvedValue, ToShmem,
+    Clone,
+    Copy,
+    Debug,
+    Eq,
+    MallocSizeOf,
+    Parse,
+    PartialEq,
+    ToComputedValue,
+    ToCss,
+    ToResolvedValue,
+    ToShmem,
 )]
 pub enum ShapeExtent {
     ClosestSide,
@@ -116,7 +132,9 @@ pub enum ShapeExtent {
 
 /// A gradient item.
 /// <https://drafts.csswg.org/css-images-4/#color-stop-syntax>
-#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, ToComputedValue, ToCss, ToResolvedValue, ToShmem)]
+#[derive(
+    Clone, Copy, Debug, MallocSizeOf, PartialEq, ToComputedValue, ToCss, ToResolvedValue, ToShmem,
+)]
 pub enum GradientItem<Color, LengthPercentage> {
     /// A color stop.
     ColorStop(ColorStop<Color, LengthPercentage>),
@@ -126,7 +144,9 @@ pub enum GradientItem<Color, LengthPercentage> {
 
 /// A color stop.
 /// <https://drafts.csswg.org/css-images/#typedef-color-stop-list>
-#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, ToComputedValue, ToCss, ToResolvedValue, ToShmem)]
+#[derive(
+    Clone, Copy, Debug, MallocSizeOf, PartialEq, ToComputedValue, ToCss, ToResolvedValue, ToShmem,
+)]
 pub struct ColorStop<Color, LengthPercentage> {
     /// The color of this stop.
     pub color: Color,
@@ -170,7 +190,15 @@ impl ToCss for PaintWorklet {
 #[allow(missing_docs)]
 #[css(comma, function)]
 #[derive(
-    Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss, ToResolvedValue, ToShmem,
+    Clone,
+    Debug,
+    MallocSizeOf,
+    PartialEq,
+    SpecifiedValueInfo,
+    ToComputedValue,
+    ToCss,
+    ToResolvedValue,
+    ToShmem,
 )]
 pub struct MozImageRect<NumberOrPercentage, MozImageRectUrl> {
     pub url: MozImageRectUrl,
diff --git a/components/style/values/generics/mod.rs b/components/style/values/generics/mod.rs
index e5bb9fa727f..d735e3bbdef 100644
--- a/components/style/values/generics/mod.rs
+++ b/components/style/values/generics/mod.rs
@@ -44,7 +44,17 @@ pub mod url;
 #[allow(missing_docs)]
 #[cfg_attr(feature = "servo", derive(Deserialize, Serialize))]
 #[derive(
-    Clone, Copy, Debug, Eq, MallocSizeOf, Parse, PartialEq, ToComputedValue, ToCss, ToResolvedValue, ToShmem,
+    Clone,
+    Copy,
+    Debug,
+    Eq,
+    MallocSizeOf,
+    Parse,
+    PartialEq,
+    ToComputedValue,
+    ToCss,
+    ToResolvedValue,
+    ToShmem,
 )]
 pub enum SymbolsType {
     Cyclic,
diff --git a/components/style/values/generics/text.rs b/components/style/values/generics/text.rs
index 6324e7dfba8..a09260aa7e4 100644
--- a/components/style/values/generics/text.rs
+++ b/components/style/values/generics/text.rs
@@ -38,9 +38,7 @@ impl<N, I> InitialLetter<N, I> {
 }
 
 /// A generic spacing value for the `letter-spacing` and `word-spacing` properties.
-#[derive(
-    Clone, Copy, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToCss, ToShmem,
-)]
+#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToCss, ToShmem)]
 pub enum Spacing<Value> {
     /// `normal`
     Normal,
@@ -75,9 +73,10 @@ impl<Value> Spacing<Value> {
 #[cfg(feature = "gecko")]
 fn line_height_moz_block_height_enabled(context: &ParserContext) -> bool {
     use crate::gecko_bindings::structs;
-    context.in_ua_sheet() || unsafe {
-        structs::StaticPrefs_sVarCache_layout_css_line_height_moz_block_height_content_enabled
-    }
+    context.in_ua_sheet() ||
+        unsafe {
+            structs::StaticPrefs_sVarCache_layout_css_line_height_moz_block_height_content_enabled
+        }
 }
 
 /// A generic value for the `line-height` property.
diff --git a/components/style/values/generics/transform.rs b/components/style/values/generics/transform.rs
index bfa59c60fb2..6c6374db941 100644
--- a/components/style/values/generics/transform.rs
+++ b/components/style/values/generics/transform.rs
@@ -132,7 +132,15 @@ fn is_same<N: PartialEq>(x: &N, y: &N) -> bool {
 }
 
 #[derive(
-    Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss, ToResolvedValue, ToShmem,
+    Clone,
+    Debug,
+    MallocSizeOf,
+    PartialEq,
+    SpecifiedValueInfo,
+    ToComputedValue,
+    ToCss,
+    ToResolvedValue,
+    ToShmem,
 )]
 /// A single operation in the list of a `transform` value
 pub enum TransformOperation<Angle, Number, Length, Integer, LengthPercentage>
@@ -239,7 +247,15 @@ where
 }
 
 #[derive(
-    Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss, ToResolvedValue, ToShmem,
+    Clone,
+    Debug,
+    MallocSizeOf,
+    PartialEq,
+    SpecifiedValueInfo,
+    ToComputedValue,
+    ToCss,
+    ToResolvedValue,
+    ToShmem,
 )]
 /// A value of the `transform` property
 pub struct Transform<T>(#[css(if_empty = "none", iterable)] pub Vec<T>);
diff --git a/components/style/values/generics/ui.rs b/components/style/values/generics/ui.rs
index 444c9a561d1..945f60fb5dd 100644
--- a/components/style/values/generics/ui.rs
+++ b/components/style/values/generics/ui.rs
@@ -11,7 +11,16 @@ use values::specified::ui::CursorKind;
 /// A generic value for the `cursor` property.
 ///
 /// https://drafts.csswg.org/css-ui/#cursor
-#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToResolvedValue, ToShmem)]
+#[derive(
+    Clone,
+    Debug,
+    MallocSizeOf,
+    PartialEq,
+    SpecifiedValueInfo,
+    ToComputedValue,
+    ToResolvedValue,
+    ToShmem,
+)]
 pub struct Cursor<Image> {
     /// The parsed images for the cursor.
     pub images: Box<[Image]>,
@@ -44,7 +53,16 @@ impl<Image: ToCss> ToCss for Cursor<Image> {
 }
 
 /// A generic value for item of `image cursors`.
-#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToResolvedValue, ToShmem)]
+#[derive(
+    Clone,
+    Debug,
+    MallocSizeOf,
+    PartialEq,
+    SpecifiedValueInfo,
+    ToComputedValue,
+    ToResolvedValue,
+    ToShmem,
+)]
 pub struct CursorImage<ImageUrl, Number> {
     /// The url to parse images from.
     pub url: ImageUrl,
diff --git a/components/style/values/mod.rs b/components/style/values/mod.rs
index 89f0de816f2..e2da4984084 100644
--- a/components/style/values/mod.rs
+++ b/components/style/values/mod.rs
@@ -96,7 +96,15 @@ where
 /// Convenience void type to disable some properties and values through types.
 #[cfg_attr(feature = "servo", derive(Deserialize, MallocSizeOf, Serialize))]
 #[derive(
-    Clone, Copy, Debug, PartialEq, SpecifiedValueInfo, ToAnimatedValue, ToComputedValue, ToCss, ToResolvedValue,
+    Clone,
+    Copy,
+    Debug,
+    PartialEq,
+    SpecifiedValueInfo,
+    ToAnimatedValue,
+    ToComputedValue,
+    ToCss,
+    ToResolvedValue,
 )]
 pub enum Impossible {}
 
@@ -155,7 +163,16 @@ impl<A: Debug, B: Debug> Debug for Either<A, B> {
 
 /// <https://drafts.csswg.org/css-values-4/#custom-idents>
 #[derive(
-    Clone, Debug, Eq, Hash, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToResolvedValue, ToShmem,
+    Clone,
+    Debug,
+    Eq,
+    Hash,
+    MallocSizeOf,
+    PartialEq,
+    SpecifiedValueInfo,
+    ToComputedValue,
+    ToResolvedValue,
+    ToShmem,
 )]
 pub struct CustomIdent(pub Atom);
 
@@ -193,7 +210,9 @@ impl ToCss for CustomIdent {
 }
 
 /// <https://drafts.csswg.org/css-animations/#typedef-keyframes-name>
-#[derive(Clone, Debug, MallocSizeOf, SpecifiedValueInfo, ToComputedValue, ToResolvedValue, ToShmem)]
+#[derive(
+    Clone, Debug, MallocSizeOf, SpecifiedValueInfo, ToComputedValue, ToResolvedValue, ToShmem,
+)]
 pub enum KeyframesName {
     /// <custom-ident>
     Ident(CustomIdent),
diff --git a/components/style/values/resolved/mod.rs b/components/style/values/resolved/mod.rs
index 33609cbd89d..7877ed71a0b 100644
--- a/components/style/values/resolved/mod.rs
+++ b/components/style/values/resolved/mod.rs
@@ -5,9 +5,9 @@
 //! Resolved values. These are almost always computed values, but in some cases
 //! there are used values.
 
+use crate::properties::ComputedValues;
 use cssparser;
 use smallvec::SmallVec;
-use crate::properties::ComputedValues;
 
 mod color;
 
@@ -182,7 +182,9 @@ where
 
     #[inline]
     fn to_resolved_value(self, context: &Context) -> Self::ResolvedValue {
-        Vec::from(self).to_resolved_value(context).into_boxed_slice()
+        Vec::from(self)
+            .to_resolved_value(context)
+            .into_boxed_slice()
     }
 
     #[inline]
diff --git a/components/style/values/specified/align.rs b/components/style/values/specified/align.rs
index 20f801d13b2..7c2ecda19a4 100644
--- a/components/style/values/specified/align.rs
+++ b/components/style/values/specified/align.rs
@@ -134,7 +134,18 @@ pub enum AxisDirection {
 /// Shared value for the `align-content` and `justify-content` properties.
 ///
 /// <https://drafts.csswg.org/css-align/#content-distribution>
-#[derive(Clone, Copy, Debug, Eq, MallocSizeOf, PartialEq, ToComputedValue, ToCss, ToResolvedValue, ToShmem)]
+#[derive(
+    Clone,
+    Copy,
+    Debug,
+    Eq,
+    MallocSizeOf,
+    PartialEq,
+    ToComputedValue,
+    ToCss,
+    ToResolvedValue,
+    ToShmem,
+)]
 #[cfg_attr(feature = "servo", derive(Deserialize, Serialize))]
 pub struct ContentDistribution {
     primary: AlignFlags,
@@ -247,7 +258,18 @@ impl ContentDistribution {
 /// Value for the `align-content` property.
 ///
 /// <https://drafts.csswg.org/css-align/#propdef-align-content>
-#[derive(Clone, Copy, Debug, Eq, MallocSizeOf, PartialEq, ToComputedValue, ToCss, ToResolvedValue, ToShmem)]
+#[derive(
+    Clone,
+    Copy,
+    Debug,
+    Eq,
+    MallocSizeOf,
+    PartialEq,
+    ToComputedValue,
+    ToCss,
+    ToResolvedValue,
+    ToShmem,
+)]
 pub struct AlignContent(pub ContentDistribution);
 
 impl Parse for AlignContent {
@@ -287,7 +309,18 @@ impl From<AlignContent> for u16 {
 /// Value for the `justify-content` property.
 ///
 /// <https://drafts.csswg.org/css-align/#propdef-justify-content>
-#[derive(Clone, Copy, Debug, Eq, MallocSizeOf, PartialEq, ToComputedValue, ToCss, ToResolvedValue, ToShmem)]
+#[derive(
+    Clone,
+    Copy,
+    Debug,
+    Eq,
+    MallocSizeOf,
+    PartialEq,
+    ToComputedValue,
+    ToCss,
+    ToResolvedValue,
+    ToShmem,
+)]
 pub struct JustifyContent(pub ContentDistribution);
 
 impl Parse for JustifyContent {
@@ -325,7 +358,18 @@ impl From<JustifyContent> for u16 {
 }
 
 /// <https://drafts.csswg.org/css-align/#self-alignment>
-#[derive(Clone, Copy, Debug, Eq, MallocSizeOf, PartialEq, ToComputedValue, ToCss, ToResolvedValue, ToShmem)]
+#[derive(
+    Clone,
+    Copy,
+    Debug,
+    Eq,
+    MallocSizeOf,
+    PartialEq,
+    ToComputedValue,
+    ToCss,
+    ToResolvedValue,
+    ToShmem,
+)]
 pub struct SelfAlignment(pub AlignFlags);
 
 impl SelfAlignment {
@@ -385,7 +429,18 @@ impl SelfAlignment {
 /// The specified value of the align-self property.
 ///
 /// <https://drafts.csswg.org/css-align/#propdef-align-self>
-#[derive(Clone, Copy, Debug, Eq, MallocSizeOf, PartialEq, ToComputedValue, ToCss, ToResolvedValue, ToShmem)]
+#[derive(
+    Clone,
+    Copy,
+    Debug,
+    Eq,
+    MallocSizeOf,
+    PartialEq,
+    ToComputedValue,
+    ToCss,
+    ToResolvedValue,
+    ToShmem,
+)]
 pub struct AlignSelf(pub SelfAlignment);
 
 impl Parse for AlignSelf {
@@ -423,7 +478,18 @@ impl From<AlignSelf> for u8 {
 /// The specified value of the justify-self property.
 ///
 /// <https://drafts.csswg.org/css-align/#propdef-justify-self>
-#[derive(Clone, Copy, Debug, Eq, MallocSizeOf, PartialEq, ToComputedValue, ToCss, ToResolvedValue, ToShmem)]
+#[derive(
+    Clone,
+    Copy,
+    Debug,
+    Eq,
+    MallocSizeOf,
+    PartialEq,
+    ToComputedValue,
+    ToCss,
+    ToResolvedValue,
+    ToShmem,
+)]
 pub struct JustifySelf(pub SelfAlignment);
 
 impl Parse for JustifySelf {
@@ -461,7 +527,18 @@ impl From<JustifySelf> for u8 {
 /// Value of the `align-items` property
 ///
 /// <https://drafts.csswg.org/css-align/#propdef-align-items>
-#[derive(Clone, Copy, Debug, Eq, MallocSizeOf, PartialEq, ToComputedValue, ToCss, ToResolvedValue, ToShmem)]
+#[derive(
+    Clone,
+    Copy,
+    Debug,
+    Eq,
+    MallocSizeOf,
+    PartialEq,
+    ToComputedValue,
+    ToCss,
+    ToResolvedValue,
+    ToShmem,
+)]
 pub struct AlignItems(pub AlignFlags);
 
 impl AlignItems {
diff --git a/components/style/values/specified/background.rs b/components/style/values/specified/background.rs
index f087695db52..e7cb98a6ae9 100644
--- a/components/style/values/specified/background.rs
+++ b/components/style/values/specified/background.rs
@@ -64,7 +64,16 @@ pub enum BackgroundRepeatKeyword {
 /// axes.
 ///
 /// https://drafts.csswg.org/css-backgrounds/#the-background-repeat
-#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToResolvedValue, ToShmem)]
+#[derive(
+    Clone,
+    Debug,
+    MallocSizeOf,
+    PartialEq,
+    SpecifiedValueInfo,
+    ToComputedValue,
+    ToResolvedValue,
+    ToShmem,
+)]
 pub struct BackgroundRepeat(pub BackgroundRepeatKeyword, pub BackgroundRepeatKeyword);
 
 impl BackgroundRepeat {
diff --git a/components/style/values/specified/border.rs b/components/style/values/specified/border.rs
index c05217fab0c..59f2f7aa284 100644
--- a/components/style/values/specified/border.rs
+++ b/components/style/values/specified/border.rs
@@ -265,7 +265,15 @@ pub enum BorderImageRepeatKeyword {
 ///
 /// https://drafts.csswg.org/css-backgrounds/#the-border-image-repeat
 #[derive(
-    Clone, Copy, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToResolvedValue, ToShmem,
+    Clone,
+    Copy,
+    Debug,
+    MallocSizeOf,
+    PartialEq,
+    SpecifiedValueInfo,
+    ToComputedValue,
+    ToResolvedValue,
+    ToShmem,
 )]
 pub struct BorderImageRepeat(pub BorderImageRepeatKeyword, pub BorderImageRepeatKeyword);
 
diff --git a/components/style/values/specified/box.rs b/components/style/values/specified/box.rs
index c003bf966bb..c90c270c59f 100644
--- a/components/style/values/specified/box.rs
+++ b/components/style/values/specified/box.rs
@@ -468,12 +468,17 @@ impl Parse for ScrollSnapType {
         _context: &ParserContext,
         input: &mut Parser<'i, 't>,
     ) -> Result<Self, ParseError<'i>> {
-        if input.try(|input| input.expect_ident_matching("none")).is_ok() {
+        if input
+            .try(|input| input.expect_ident_matching("none"))
+            .is_ok()
+        {
             return Ok(ScrollSnapType::none());
         }
 
         let axis = ScrollSnapAxis::parse(input)?;
-        let strictness = input.try(ScrollSnapStrictness::parse).unwrap_or(ScrollSnapStrictness::Proximity);
+        let strictness = input
+            .try(ScrollSnapStrictness::parse)
+            .unwrap_or(ScrollSnapStrictness::Proximity);
         Ok(Self { axis, strictness })
     }
 }
@@ -524,7 +529,16 @@ pub enum ScrollSnapAlignKeyword {
 /// https://drafts.csswg.org/css-scroll-snap-1/#scroll-snap-align
 #[allow(missing_docs)]
 #[derive(
-    Clone, Copy, Debug, Eq, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToResolvedValue, ToShmem,
+    Clone,
+    Copy,
+    Debug,
+    Eq,
+    MallocSizeOf,
+    PartialEq,
+    SpecifiedValueInfo,
+    ToComputedValue,
+    ToResolvedValue,
+    ToShmem,
 )]
 #[repr(C)]
 pub struct ScrollSnapAlign {
@@ -637,7 +651,15 @@ pub enum OverflowClipBox {
 }
 
 #[derive(
-    Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss, ToResolvedValue, ToShmem,
+    Clone,
+    Debug,
+    MallocSizeOf,
+    PartialEq,
+    SpecifiedValueInfo,
+    ToComputedValue,
+    ToCss,
+    ToResolvedValue,
+    ToShmem,
 )]
 /// Provides a rendering hint to the user agent,
 /// stating what kinds of changes the author expects
@@ -940,7 +962,9 @@ pub type Perspective = GenericPerspective<NonNegativeLength>;
 
 /// A given transition property, that is either `All`, a longhand or shorthand
 /// property, or an unsupported or custom property.
-#[derive(Clone, Debug, Eq, Hash, MallocSizeOf, PartialEq, ToComputedValue, ToResolvedValue, ToShmem)]
+#[derive(
+    Clone, Debug, Eq, Hash, MallocSizeOf, PartialEq, ToComputedValue, ToResolvedValue, ToShmem,
+)]
 pub enum TransitionProperty {
     /// A shorthand.
     Shorthand(ShorthandId),
@@ -1035,17 +1059,7 @@ impl TransitionProperty {
 #[allow(missing_docs)]
 #[cfg_attr(feature = "servo", derive(Deserialize, Serialize))]
 #[derive(
-    Clone,
-    Copy,
-    Debug,
-    Eq,
-    Hash,
-    MallocSizeOf,
-    Parse,
-    PartialEq,
-    SpecifiedValueInfo,
-    ToCss,
-    ToShmem,
+    Clone, Copy, Debug, Eq, Hash, MallocSizeOf, Parse, PartialEq, SpecifiedValueInfo, ToCss, ToShmem,
 )]
 /// https://drafts.csswg.org/css-box/#propdef-float
 pub enum Float {
@@ -1060,17 +1074,7 @@ pub enum Float {
 #[allow(missing_docs)]
 #[cfg_attr(feature = "servo", derive(Deserialize, Serialize))]
 #[derive(
-    Clone,
-    Copy,
-    Debug,
-    Eq,
-    Hash,
-    MallocSizeOf,
-    Parse,
-    PartialEq,
-    SpecifiedValueInfo,
-    ToCss,
-    ToShmem,
+    Clone, Copy, Debug, Eq, Hash, MallocSizeOf, Parse, PartialEq, SpecifiedValueInfo, ToCss, ToShmem,
 )]
 /// https://drafts.csswg.org/css-box/#propdef-clear
 pub enum Clear {
@@ -1087,17 +1091,7 @@ pub enum Clear {
 #[allow(missing_docs)]
 #[cfg_attr(feature = "servo", derive(Deserialize, Serialize))]
 #[derive(
-    Clone,
-    Copy,
-    Debug,
-    Eq,
-    Hash,
-    MallocSizeOf,
-    Parse,
-    PartialEq,
-    SpecifiedValueInfo,
-    ToCss,
-    ToShmem,
+    Clone, Copy, Debug, Eq, Hash, MallocSizeOf, Parse, PartialEq, SpecifiedValueInfo, ToCss, ToShmem,
 )]
 pub enum Resize {
     None,
diff --git a/components/style/values/specified/color.rs b/components/style/values/specified/color.rs
index 25e7af6b98b..375a7d23d49 100644
--- a/components/style/values/specified/color.rs
+++ b/components/style/values/specified/color.rs
@@ -407,7 +407,9 @@ impl ToComputedValue for MozFontSmoothingBackgroundColor {
     type ComputedValue = RGBA;
 
     fn to_computed_value(&self, context: &Context) -> RGBA {
-        self.0.to_computed_value(context).to_rgba(RGBA::transparent())
+        self.0
+            .to_computed_value(context)
+            .to_rgba(RGBA::transparent())
     }
 
     fn from_computed_value(computed: &RGBA) -> Self {
diff --git a/components/style/values/specified/font.rs b/components/style/values/specified/font.rs
index 809ffe77498..f02d44124a2 100644
--- a/components/style/values/specified/font.rs
+++ b/components/style/values/specified/font.rs
@@ -368,9 +368,7 @@ pub enum FontStretch {
 }
 
 /// A keyword value for `font-stretch`.
-#[derive(
-    Clone, Copy, Debug, MallocSizeOf, Parse, PartialEq, SpecifiedValueInfo, ToCss, ToShmem,
-)]
+#[derive(Clone, Copy, Debug, MallocSizeOf, Parse, PartialEq, SpecifiedValueInfo, ToCss, ToShmem)]
 #[allow(missing_docs)]
 pub enum FontStretchKeyword {
     Normal,
@@ -532,7 +530,9 @@ impl FontFamily {
     /// Parse a specified font-family value
     pub fn parse_specified<'i, 't>(input: &mut Parser<'i, 't>) -> Result<Self, ParseError<'i>> {
         let values = input.parse_comma_separated(SingleFontFamily::parse)?;
-        Ok(FontFamily::Values(FontFamilyList::new(values.into_boxed_slice())))
+        Ok(FontFamily::Values(FontFamilyList::new(
+            values.into_boxed_slice(),
+        )))
     }
 }
 
@@ -995,7 +995,9 @@ bitflags! {
     }
 }
 
-#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToCss, ToResolvedValue, ToShmem)]
+#[derive(
+    Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToCss, ToResolvedValue, ToShmem,
+)]
 /// Set of variant alternates
 pub enum VariantAlternates {
     /// Enables display of stylistic alternates
@@ -1020,7 +1022,9 @@ pub enum VariantAlternates {
     HistoricalForms,
 }
 
-#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToCss, ToResolvedValue, ToShmem)]
+#[derive(
+    Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToCss, ToResolvedValue, ToShmem,
+)]
 /// List of Variant Alternates
 pub struct VariantAlternatesList(
     #[css(if_empty = "normal", iterable)] pub Box<[VariantAlternates]>,
@@ -1858,7 +1862,15 @@ impl Parse for FontFeatureSettings {
 }
 
 #[derive(
-    Clone, Copy, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToResolvedValue, ToShmem,
+    Clone,
+    Copy,
+    Debug,
+    MallocSizeOf,
+    PartialEq,
+    SpecifiedValueInfo,
+    ToComputedValue,
+    ToResolvedValue,
+    ToShmem,
 )]
 /// Whether user agents are allowed to synthesize bold or oblique font faces
 /// when a font family lacks bold or italic faces
@@ -2178,7 +2190,15 @@ impl Parse for XTextZoom {
 }
 
 #[derive(
-    Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss, ToResolvedValue, ToShmem,
+    Clone,
+    Debug,
+    MallocSizeOf,
+    PartialEq,
+    SpecifiedValueInfo,
+    ToComputedValue,
+    ToCss,
+    ToResolvedValue,
+    ToShmem,
 )]
 /// Internal property that reflects the lang attribute
 pub struct XLang(#[css(skip)] pub Atom);
@@ -2267,7 +2287,17 @@ impl Parse for MozScriptLevel {
 }
 
 #[cfg_attr(feature = "gecko", derive(MallocSizeOf))]
-#[derive(Clone, Copy, Debug, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss, ToResolvedValue, ToShmem)]
+#[derive(
+    Clone,
+    Copy,
+    Debug,
+    PartialEq,
+    SpecifiedValueInfo,
+    ToComputedValue,
+    ToCss,
+    ToResolvedValue,
+    ToShmem,
+)]
 /// Specifies the multiplier to be used to adjust font size
 /// due to changes in scriptlevel.
 ///
diff --git a/components/style/values/specified/length.rs b/components/style/values/specified/length.rs
index a6beef91ee5..5bb01955956 100644
--- a/components/style/values/specified/length.rs
+++ b/components/style/values/specified/length.rs
@@ -13,8 +13,7 @@ use crate::properties::computed_value_flags::ComputedValueFlags;
 use crate::values::computed::{self, CSSPixelLength, Context};
 use crate::values::generics::length as generics;
 use crate::values::generics::length::{
-    GenericLengthPercentageOrNormal, GenericLengthOrNumber,
-    GenericMaxSize, GenericSize,
+    GenericLengthOrNumber, GenericLengthPercentageOrNormal, GenericMaxSize, GenericSize,
 };
 use crate::values::generics::NonNegative;
 use crate::values::specified::calc::CalcNode;
@@ -958,7 +957,8 @@ impl NonNegativeLengthPercentageOrAuto {
 pub type NonNegativeLengthPercentage = NonNegative<LengthPercentage>;
 
 /// Either a NonNegativeLengthPercentage or the `normal` keyword.
-pub type NonNegativeLengthPercentageOrNormal = GenericLengthPercentageOrNormal<NonNegativeLengthPercentage>;
+pub type NonNegativeLengthPercentageOrNormal =
+    GenericLengthPercentageOrNormal<NonNegativeLengthPercentage>;
 
 impl From<NoCalcLength> for NonNegativeLengthPercentage {
     #[inline]
diff --git a/components/style/values/specified/list.rs b/components/style/values/specified/list.rs
index 5a95a9bd7f7..8c1e9fa2ad4 100644
--- a/components/style/values/specified/list.rs
+++ b/components/style/values/specified/list.rs
@@ -16,7 +16,16 @@ use style_traits::{ParseError, StyleParseErrorKind};
 /// Specified and computed `list-style-type` property.
 #[cfg(feature = "gecko")]
 #[derive(
-    Clone, Debug, Eq, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss, ToResolvedValue, ToShmem,
+    Clone,
+    Debug,
+    Eq,
+    MallocSizeOf,
+    PartialEq,
+    SpecifiedValueInfo,
+    ToComputedValue,
+    ToCss,
+    ToResolvedValue,
+    ToShmem,
 )]
 pub enum ListStyleType {
     /// <counter-style> | none
@@ -77,7 +86,15 @@ impl Parse for ListStyleType {
 
 /// A quote pair.
 #[derive(
-    Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss, ToResolvedValue, ToShmem,
+    Clone,
+    Debug,
+    MallocSizeOf,
+    PartialEq,
+    SpecifiedValueInfo,
+    ToComputedValue,
+    ToCss,
+    ToResolvedValue,
+    ToShmem,
 )]
 pub struct QuotePair {
     /// The opening quote.
@@ -89,7 +106,15 @@ pub struct QuotePair {
 
 /// Specified and computed `quotes` property.
 #[derive(
-    Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss, ToResolvedValue, ToShmem,
+    Clone,
+    Debug,
+    MallocSizeOf,
+    PartialEq,
+    SpecifiedValueInfo,
+    ToComputedValue,
+    ToCss,
+    ToResolvedValue,
+    ToShmem,
 )]
 pub struct Quotes(
     #[css(iterable, if_empty = "none")]
diff --git a/components/style/values/specified/mod.rs b/components/style/values/specified/mod.rs
index 5c9e413cb09..64a76ccc582 100644
--- a/components/style/values/specified/mod.rs
+++ b/components/style/values/specified/mod.rs
@@ -709,7 +709,15 @@ impl AllowQuirks {
 ///
 /// `[namespace? `|`]? ident`
 #[derive(
-    Clone, Debug, Eq, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToResolvedValue, ToShmem,
+    Clone,
+    Debug,
+    Eq,
+    MallocSizeOf,
+    PartialEq,
+    SpecifiedValueInfo,
+    ToComputedValue,
+    ToResolvedValue,
+    ToShmem,
 )]
 #[css(function)]
 pub struct Attr {
diff --git a/components/style/values/specified/position.rs b/components/style/values/specified/position.rs
index d3c39b4f582..f75af3f5585 100644
--- a/components/style/values/specified/position.rs
+++ b/components/style/values/specified/position.rs
@@ -571,7 +571,17 @@ impl From<GridAutoFlow> for u8 {
     }
 }
 
-#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss, ToResolvedValue, ToShmem)]
+#[derive(
+    Clone,
+    Debug,
+    MallocSizeOf,
+    PartialEq,
+    SpecifiedValueInfo,
+    ToComputedValue,
+    ToCss,
+    ToResolvedValue,
+    ToShmem,
+)]
 /// https://drafts.csswg.org/css-grid/#named-grid-area
 pub struct TemplateAreas {
     /// `named area` containing for each template area
@@ -678,7 +688,15 @@ impl Parse for TemplateAreas {
 
 /// Arc type for `Arc<TemplateAreas>`
 #[derive(
-    Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss, ToResolvedValue, ToShmem,
+    Clone,
+    Debug,
+    MallocSizeOf,
+    PartialEq,
+    SpecifiedValueInfo,
+    ToComputedValue,
+    ToCss,
+    ToResolvedValue,
+    ToShmem,
 )]
 pub struct TemplateAreasArc(#[ignore_malloc_size_of = "Arc"] pub Arc<TemplateAreas>);
 
diff --git a/components/style/values/specified/svg.rs b/components/style/values/specified/svg.rs
index b78b11f2ffa..dd4990782a0 100644
--- a/components/style/values/specified/svg.rs
+++ b/components/style/values/specified/svg.rs
@@ -129,7 +129,15 @@ const PAINT_ORDER_MASK: u8 = 0b11;
 /// Higher priority values, i.e. the values specified first,
 /// will be painted first (and may be covered by paintings of lower priority)
 #[derive(
-    Clone, Copy, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToResolvedValue, ToShmem,
+    Clone,
+    Copy,
+    Debug,
+    MallocSizeOf,
+    PartialEq,
+    SpecifiedValueInfo,
+    ToComputedValue,
+    ToResolvedValue,
+    ToShmem,
 )]
 pub struct SVGPaintOrder(pub u8);
 
@@ -238,7 +246,15 @@ impl ToCss for SVGPaintOrder {
 /// Specified MozContextProperties value.
 /// Nonstandard (https://developer.mozilla.org/en-US/docs/Web/CSS/-moz-context-properties)
 #[derive(
-    Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToCss, ToResolvedValue, ToShmem,
+    Clone,
+    Debug,
+    MallocSizeOf,
+    PartialEq,
+    SpecifiedValueInfo,
+    ToComputedValue,
+    ToCss,
+    ToResolvedValue,
+    ToShmem,
 )]
 pub struct MozContextProperties(pub CustomIdent);
 
diff --git a/components/style/values/specified/text.rs b/components/style/values/specified/text.rs
index 44df9a4c38e..9d4c6ae649c 100644
--- a/components/style/values/specified/text.rs
+++ b/components/style/values/specified/text.rs
@@ -512,9 +512,7 @@ impl TextEmphasisKeywordValue {
 }
 
 /// Fill mode for the text-emphasis-style property
-#[derive(
-    Clone, Copy, Debug, MallocSizeOf, Parse, PartialEq, SpecifiedValueInfo, ToCss, ToShmem,
-)]
+#[derive(Clone, Copy, Debug, MallocSizeOf, Parse, PartialEq, SpecifiedValueInfo, ToCss, ToShmem)]
 pub enum TextEmphasisFillMode {
     /// `filled`
     Filled,
diff --git a/components/style/values/specified/ui.rs b/components/style/values/specified/ui.rs
index 52afa0fb256..0cc20d960c6 100644
--- a/components/style/values/specified/ui.rs
+++ b/components/style/values/specified/ui.rs
@@ -57,7 +57,15 @@ impl Parse for CursorImage {
 
 /// Specified value of `-moz-force-broken-image-icon`
 #[derive(
-    Clone, Copy, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToComputedValue, ToResolvedValue, ToShmem,
+    Clone,
+    Copy,
+    Debug,
+    MallocSizeOf,
+    PartialEq,
+    SpecifiedValueInfo,
+    ToComputedValue,
+    ToResolvedValue,
+    ToShmem,
 )]
 pub struct MozForceBrokenImageIcon(pub bool);
 
diff --git a/components/style_derive/to_animated_value.rs b/components/style_derive/to_animated_value.rs
index ac231be3452..51a73cbf4e1 100644
--- a/components/style_derive/to_animated_value.rs
+++ b/components/style_derive/to_animated_value.rs
@@ -10,20 +10,20 @@ use to_computed_value;
 pub fn derive(input: DeriveInput) -> TokenStream {
     let trait_impl = |from_body, to_body| {
         quote! {
-            #[inline]
-            fn from_animated_value(animated: Self::AnimatedValue) -> Self {
-                match animated {
-                    #from_body
-                }
-            }
+             #[inline]
+             fn from_animated_value(animated: Self::AnimatedValue) -> Self {
+                 match animated {
+                     #from_body
+                 }
+             }
 
-            #[inline]
-            fn to_animated_value(self) -> Self::AnimatedValue {
-                match self {
-                    #to_body
-                }
-            }
-       }
+             #[inline]
+             fn to_animated_value(self) -> Self::AnimatedValue {
+                 match self {
+                     #to_body
+                 }
+             }
+        }
     };
 
     // TODO(emilio): Consider optimizing away non-generic cases as well?
diff --git a/components/style_derive/to_computed_value.rs b/components/style_derive/to_computed_value.rs
index 6010b7483cb..ed6e07a2f5a 100644
--- a/components/style_derive/to_computed_value.rs
+++ b/components/style_derive/to_computed_value.rs
@@ -55,10 +55,7 @@ pub fn derive_to_value(
     let (to_body, from_body) = {
         let params = input.generics.type_params().collect::<Vec<_>>();
         for param in &params {
-            cg::add_predicate(
-                &mut where_clause,
-                parse_quote!(#param: #trait_path),
-            );
+            cg::add_predicate(&mut where_clause, parse_quote!(#param: #trait_path));
         }
 
         let to_body = cg::fmap_match(&input, bind_style, |binding| {
@@ -80,20 +77,14 @@ pub fn derive_to_value(
             }
             call_to(&binding)
         });
-        let from_body = cg::fmap_match(&input, bind_style, |binding| {
-            call_from(&binding)
-        });
+        let from_body = cg::fmap_match(&input, bind_style, |binding| call_from(&binding));
 
         (to_body, from_body)
     };
 
     input.generics.where_clause = where_clause;
     let (impl_generics, ty_generics, where_clause) = input.generics.split_for_impl();
-    let computed_value_type = cg::fmap_trait_output(
-        &input,
-        &trait_path,
-        &output_type_name,
-    );
+    let computed_value_type = cg::fmap_trait_output(&input, &trait_path, &output_type_name);
 
     let impl_ = trait_impl(from_body, to_body);
 
@@ -109,21 +100,21 @@ pub fn derive_to_value(
 pub fn derive(input: DeriveInput) -> TokenStream {
     let trait_impl = |from_body, to_body| {
         quote! {
-            #[inline]
-            fn from_computed_value(computed: &Self::ComputedValue) -> Self {
-                match *computed {
-                    #from_body
-                }
-            }
+             #[inline]
+             fn from_computed_value(computed: &Self::ComputedValue) -> Self {
+                 match *computed {
+                     #from_body
+                 }
+             }
 
-            #[allow(unused_variables)]
-            #[inline]
-            fn to_computed_value(&self, context: &crate::values::computed::Context) -> Self::ComputedValue {
-                match *self {
-                    #to_body
-                }
-            }
-       }
+             #[allow(unused_variables)]
+             #[inline]
+             fn to_computed_value(&self, context: &crate::values::computed::Context) -> Self::ComputedValue {
+                 match *self {
+                     #to_body
+                 }
+             }
+        }
     };
 
     let non_generic_implementation = || {
diff --git a/components/style_derive/to_resolved_value.rs b/components/style_derive/to_resolved_value.rs
index 70d3f71876f..040cda954a8 100644
--- a/components/style_derive/to_resolved_value.rs
+++ b/components/style_derive/to_resolved_value.rs
@@ -11,23 +11,23 @@ use to_computed_value;
 pub fn derive(input: DeriveInput) -> TokenStream {
     let trait_impl = |from_body, to_body| {
         quote! {
-            #[inline]
-            fn from_resolved_value(resolved: Self::ResolvedValue) -> Self {
-                match resolved {
-                    #from_body
-                }
-            }
+             #[inline]
+             fn from_resolved_value(resolved: Self::ResolvedValue) -> Self {
+                 match resolved {
+                     #from_body
+                 }
+             }
 
-            #[inline]
-            fn to_resolved_value(
-                self,
-                context: &crate::values::resolved::Context,
-            ) -> Self::ResolvedValue {
-                match self {
-                    #to_body
-                }
-            }
-       }
+             #[inline]
+             fn to_resolved_value(
+                 self,
+                 context: &crate::values::resolved::Context,
+             ) -> Self::ResolvedValue {
+                 match self {
+                     #to_body
+                 }
+             }
+        }
     };
 
     let non_generic_implementation = || {
diff --git a/components/to_shmem/lib.rs b/components/to_shmem/lib.rs
index db6efe20895..59fc2afb546 100644
--- a/components/to_shmem/lib.rs
+++ b/components/to_shmem/lib.rs
@@ -24,17 +24,17 @@ use smallvec::{Array, SmallVec};
 use std::alloc::Layout;
 #[cfg(debug_assertions)]
 use std::any::TypeId;
-use std::isize;
 #[cfg(debug_assertions)]
 use std::collections::HashSet;
 use std::ffi::CString;
+use std::isize;
 use std::marker::PhantomData;
 use std::mem::{self, ManuallyDrop};
 use std::num::Wrapping;
 use std::ops::Range;
+use std::os::raw::c_char;
 #[cfg(debug_assertions)]
 use std::os::raw::c_void;
-use std::os::raw::c_char;
 use std::ptr::{self, NonNull};
 use std::slice;
 use std::str;
@@ -166,7 +166,7 @@ impl SharedMemoryBuilder {
 
         // Reserve space for the padding.
         let start = self.index.checked_add(padding).unwrap();
-        assert!(start <= std::isize::MAX as usize);  // for the cast below
+        assert!(start <= std::isize::MAX as usize); // for the cast below
 
         // Reserve space for the value.
         let end = start.checked_add(layout.size()).unwrap();
@@ -205,7 +205,22 @@ macro_rules! impl_trivial_to_shmem {
     )*};
 }
 
-impl_trivial_to_shmem!((), bool, f32, f64, i8, i16, i32, i64, u8, u16, u32, u64, isize, usize);
+impl_trivial_to_shmem!(
+    (),
+    bool,
+    f32,
+    f64,
+    i8,
+    i16,
+    i32,
+    i64,
+    u8,
+    u16,
+    u32,
+    u64,
+    isize,
+    usize
+);
 
 impl_trivial_to_shmem!(cssparser::RGBA);
 impl_trivial_to_shmem!(cssparser::SourceLocation);
@@ -424,7 +439,9 @@ impl<T: 'static + ToShmem> ToShmem for Arc<T> {
         #[cfg(debug_assertions)]
         assert!(
             !builder.shared_values.contains(&self.heap_ptr()) ||
-            builder.allowed_duplication_types.contains(&TypeId::of::<T>()),
+                builder
+                    .allowed_duplication_types
+                    .contains(&TypeId::of::<T>()),
             "ToShmem failed for Arc<T>: encountered a value of type T with multiple references \
              and which has not been explicitly allowed with an add_allowed_duplication_type call",
         );
@@ -463,11 +480,7 @@ impl<H: 'static + ToShmem, T: 'static + ToShmem> ToShmem for ThinArc<H, T> {
         // Make a clone of the Arc-owned header and slice values with all of
         // their heap allocations placed in the shared memory buffer.
         let header = self.header.header.to_shmem(builder);
-        let values: Vec<ManuallyDrop<T>> = self
-            .slice
-            .iter()
-            .map(|v| v.to_shmem(builder))
-            .collect();
+        let values: Vec<ManuallyDrop<T>> = self.slice.iter().map(|v| v.to_shmem(builder)).collect();
 
         // Create a new ThinArc with the shared value and have it place
         // its ArcInner in the shared memory buffer.
@@ -499,10 +512,11 @@ impl ToShmem for SmallBitVec {
                     let src = vs.as_ptr() as *const usize;
                     ptr::copy(src, dest, len);
 
-                    let dest_slice = Box::from_raw(slice::from_raw_parts_mut(dest, len) as *mut [usize]);
+                    let dest_slice =
+                        Box::from_raw(slice::from_raw_parts_mut(dest, len) as *mut [usize]);
                     InternalStorage::Spilled(dest_slice)
                 }
-            }
+            },
             InternalStorage::Inline(x) => InternalStorage::Inline(x),
         };
         ManuallyDrop::new(unsafe { SmallBitVec::from_storage(storage) })
diff --git a/components/to_shmem_derive/to_shmem.rs b/components/to_shmem_derive/to_shmem.rs
index 5021476aad4..1335ef4eea6 100644
--- a/components/to_shmem_derive/to_shmem.rs
+++ b/components/to_shmem_derive/to_shmem.rs
@@ -12,10 +12,7 @@ pub fn derive(mut input: syn::DeriveInput) -> TokenStream {
     let attrs = cg::parse_input_attrs::<ShmemInputAttrs>(&input);
     if !attrs.no_bounds {
         for param in input.generics.type_params() {
-            cg::add_predicate(
-                &mut where_clause,
-                parse_quote!(#param: ::to_shmem::ToShmem),
-            );
+            cg::add_predicate(&mut where_clause, parse_quote!(#param: ::to_shmem::ToShmem));
         }
     }
     for variant in Structure::new(&input).variants() {
@@ -23,10 +20,7 @@ pub fn derive(mut input: syn::DeriveInput) -> TokenStream {
             let attrs = cg::parse_field_attrs::<ShmemFieldAttrs>(&binding.ast());
             if attrs.field_bound {
                 let ty = &binding.ast().ty;
-                cg::add_predicate(
-                    &mut where_clause,
-                    parse_quote!(#ty: ::to_shmem::ToShmem),
-                )
+                cg::add_predicate(&mut where_clause, parse_quote!(#ty: ::to_shmem::ToShmem))
             }
         }
     }

From 49842f50312787fc4f89c88536d7fc9e87583b06 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Emilio=20Cobos=20=C3=81lvarez?= <emilio@crisal.io>
Date: Thu, 11 Apr 2019 22:16:56 +0200
Subject: [PATCH 56/59] style: Fix servo build, and appease tidy / fmt.

---
 Cargo.lock                                    | 45 +++++++++++++++++++
 components/gfx/font.rs                        | 13 ++++--
 components/layout/multicol.rs                 | 11 +++--
 components/script/dom/element.rs              |  1 +
 components/style/Cargo.toml                   |  2 +-
 components/style/font_metrics.rs              |  2 +-
 components/style/gecko/url.rs                 |  2 +-
 .../style/properties/declaration_block.rs     |  2 +-
 .../style/properties/longhands/font.mako.rs   |  3 +-
 components/style/servo/selector_parser.rs     |  6 +--
 components/style/servo/url.rs                 |  4 +-
 components/style/shared_lock.rs               | 21 ++++-----
 components/style/stylesheets/mod.rs           |  1 +
 components/style/values/computed/font.rs      | 41 +++++++++++++++--
 components/style/values/generics/grid.rs      |  2 +-
 components/style/values/generics/image.rs     |  2 +-
 components/style/values/resolved/mod.rs       |  5 ++-
 components/style/values/specified/font.rs     |  2 +-
 components/to_shmem/Cargo.toml                |  5 ++-
 components/to_shmem/lib.rs                    | 36 +++++++++++----
 components/to_shmem_derive/to_shmem.rs        |  2 +-
 components/url/Cargo.toml                     |  2 +
 components/url/lib.rs                         |  8 ++++
 23 files changed, 165 insertions(+), 53 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index ea625f81909..8164783500d 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -942,6 +942,17 @@ dependencies = [
  "deny_public_fields 0.0.1",
 ]
 
+[[package]]
+name = "derive_common"
+version = "0.0.1"
+dependencies = [
+ "darling 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "proc-macro2 0.4.26 (registry+https://github.com/rust-lang/crates.io-index)",
+ "quote 0.6.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "syn 0.15.22 (registry+https://github.com/rust-lang/crates.io-index)",
+ "synstructure 0.10.1 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "derive_more"
 version = "0.13.0"
@@ -3646,6 +3657,8 @@ dependencies = [
  "servo_arc 0.1.1",
  "smallvec 0.6.7 (registry+https://github.com/rust-lang/crates.io-index)",
  "thin-slice 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "to_shmem 0.0.1",
+ "to_shmem_derive 0.0.1",
 ]
 
 [[package]]
@@ -3992,6 +4005,8 @@ dependencies = [
  "malloc_size_of_derive 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.80 (registry+https://github.com/rust-lang/crates.io-index)",
  "servo_rand 0.0.1",
+ "to_shmem 0.0.1",
+ "to_shmem_derive 0.0.1",
  "url 1.7.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "url_serde 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "uuid 0.7.1 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -4240,6 +4255,8 @@ dependencies = [
  "style_traits 0.0.1",
  "thin-slice 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "time 0.1.42 (registry+https://github.com/rust-lang/crates.io-index)",
+ "to_shmem 0.0.1",
+ "to_shmem_derive 0.0.1",
  "toml 0.4.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "uluru 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "unicode-bidi 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -4253,6 +4270,7 @@ name = "style_derive"
 version = "0.0.1"
 dependencies = [
  "darling 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "derive_common 0.0.1",
  "proc-macro2 0.4.26 (registry+https://github.com/rust-lang/crates.io-index)",
  "quote 0.6.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "syn 0.15.22 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -4297,6 +4315,8 @@ dependencies = [
  "servo_arc 0.1.1",
  "servo_atoms 0.0.1",
  "servo_url 0.0.1",
+ "to_shmem 0.0.1",
+ "to_shmem_derive 0.0.1",
  "webrender_api 0.60.0 (git+https://github.com/servo/webrender)",
 ]
 
@@ -4435,6 +4455,31 @@ dependencies = [
  "libc 0.2.44 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "to_shmem"
+version = "0.0.1"
+dependencies = [
+ "cssparser 0.25.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "serde 1.0.80 (registry+https://github.com/rust-lang/crates.io-index)",
+ "servo_arc 0.1.1",
+ "smallbitvec 2.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "smallvec 0.6.7 (registry+https://github.com/rust-lang/crates.io-index)",
+ "string_cache 0.7.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "thin-slice 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "to_shmem_derive"
+version = "0.0.1"
+dependencies = [
+ "darling 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "derive_common 0.0.1",
+ "proc-macro2 0.4.26 (registry+https://github.com/rust-lang/crates.io-index)",
+ "quote 0.6.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "syn 0.15.22 (registry+https://github.com/rust-lang/crates.io-index)",
+ "synstructure 0.10.1 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "tokio"
 version = "0.1.8"
diff --git a/components/gfx/font.rs b/components/gfx/font.rs
index cd9513a3f43..35ce19621ac 100644
--- a/components/gfx/font.rs
+++ b/components/gfx/font.rs
@@ -26,7 +26,7 @@ use std::sync::atomic::{AtomicUsize, Ordering};
 use std::sync::Arc;
 use style::computed_values::{font_stretch, font_style, font_variant_caps, font_weight};
 use style::properties::style_structs::Font as FontStyleStruct;
-use style::values::computed::font::SingleFontFamily;
+use style::values::computed::font::{GenericFontFamily, SingleFontFamily};
 use unicode_script::Script;
 
 macro_rules! ot_tag {
@@ -564,9 +564,14 @@ impl<'a> From<&'a SingleFontFamily> for FontFamilyName {
                 FontFamilyName::Specific(family_name.name.clone())
             },
 
-            SingleFontFamily::Generic(ref generic_name) => {
-                FontFamilyName::Generic(generic_name.clone())
-            },
+            SingleFontFamily::Generic(generic) => FontFamilyName::Generic(match generic {
+                GenericFontFamily::None => panic!("Shouldn't appear in style"),
+                GenericFontFamily::Serif => atom!("serif"),
+                GenericFontFamily::SansSerif => atom!("sans-serif"),
+                GenericFontFamily::Monospace => atom!("monospace"),
+                GenericFontFamily::Cursive => atom!("cursive"),
+                GenericFontFamily::Fantasy => atom!("fantasy"),
+            }),
         }
     }
 }
diff --git a/components/layout/multicol.rs b/components/layout/multicol.rs
index f8ddfa8200c..46ccbc64653 100644
--- a/components/layout/multicol.rs
+++ b/components/layout/multicol.rs
@@ -19,9 +19,10 @@ use std::fmt;
 use std::sync::Arc;
 use style::logical_geometry::LogicalSize;
 use style::properties::ComputedValues;
-use style::values::computed::length::{MaxSize, NonNegativeLengthOrAuto, Size};
+use style::values::computed::length::{
+    MaxSize, NonNegativeLengthOrAuto, NonNegativeLengthPercentageOrNormal, Size,
+};
 use style::values::generics::column::ColumnCount;
-use style::values::Either;
 
 #[allow(unsafe_code)]
 unsafe impl crate::flow::HasBaseFlow for MulticolFlow {}
@@ -106,8 +107,10 @@ impl Flow for MulticolFlow {
         {
             let style = &self.block_flow.fragment.style;
             let column_gap = match style.get_position().column_gap {
-                Either::First(len) => len.0.to_pixel_length(content_inline_size).into(),
-                Either::Second(_normal) => {
+                NonNegativeLengthPercentageOrNormal::LengthPercentage(len) => {
+                    len.0.to_pixel_length(content_inline_size).into()
+                },
+                NonNegativeLengthPercentageOrNormal::Normal => {
                     self.block_flow.fragment.style.get_font().font_size.size()
                 },
             };
diff --git a/components/script/dom/element.rs b/components/script/dom/element.rs
index eb48c22865b..6da5d92fdb1 100644
--- a/components/script/dom/element.rs
+++ b/components/script/dom/element.rs
@@ -643,6 +643,7 @@ impl LayoutElementHelpers for LayoutDom<Element> {
         };
 
         if let Some(font_family) = font_family {
+            // FIXME(emilio): This in Gecko parses a whole family list.
             hints.push(from_declaration(
                 shared_lock,
                 PropertyDeclaration::FontFamily(font_family::SpecifiedValue::Values(
diff --git a/components/style/Cargo.toml b/components/style/Cargo.toml
index 005924cec21..0bc745015fd 100644
--- a/components/style/Cargo.toml
+++ b/components/style/Cargo.toml
@@ -20,7 +20,7 @@ gecko = ["style_traits/gecko", "fallible/known_system_malloc"]
 use_bindgen = ["bindgen", "regex", "toml"]
 servo = ["serde", "style_traits/servo", "servo_atoms", "servo_config", "html5ever",
          "cssparser/serde", "encoding_rs", "malloc_size_of/servo", "arrayvec/use_union",
-         "servo_url", "string_cache", "crossbeam-channel"]
+         "servo_url", "string_cache", "crossbeam-channel", "to_shmem/servo", "servo_arc/servo"]
 gecko_debug = []
 
 [dependencies]
diff --git a/components/style/font_metrics.rs b/components/style/font_metrics.rs
index a45ebc297d9..8e69118ade4 100644
--- a/components/style/font_metrics.rs
+++ b/components/style/font_metrics.rs
@@ -70,7 +70,7 @@ impl FontMetricsProvider for ServoMetricsProvider {
         ServoMetricsProvider
     }
 
-    fn get_size(&self, _font_name: &Atom, _font_family: u8) -> Au {
+    fn get_size(&self, _: &Atom, _: crate::values::computed::font::GenericFontFamily) -> Au {
         unreachable!("Dummy provider should never be used to compute font size")
     }
 }
diff --git a/components/style/gecko/url.rs b/components/style/gecko/url.rs
index 2c61ab4db0b..2da16043779 100644
--- a/components/style/gecko/url.rs
+++ b/components/style/gecko/url.rs
@@ -123,7 +123,7 @@ impl MallocSizeOf for CssUrl {
 }
 
 /// A key type for URL_VALUE_TABLE.
-#[derive(Hash, PartialEq, Eq)]
+#[derive(Eq, Hash, PartialEq)]
 struct CssUrlDataKey(*const CssUrlData);
 
 unsafe impl Sync for CssUrlDataKey {}
diff --git a/components/style/properties/declaration_block.rs b/components/style/properties/declaration_block.rs
index c86f5bac9ee..42fc833e4b9 100644
--- a/components/style/properties/declaration_block.rs
+++ b/components/style/properties/declaration_block.rs
@@ -25,7 +25,7 @@ use style_traits::{CssWriter, ParseError, ParsingMode, StyleParseErrorKind, ToCs
 use crate::stylesheets::{CssRuleType, Origin, UrlExtraData};
 use super::*;
 use crate::values::computed::Context;
-use crate::selector_parser::{SelectorImpl};
+use crate::selector_parser::SelectorImpl;
 use selectors::SelectorList;
 
 /// The animation rules.
diff --git a/components/style/properties/longhands/font.mako.rs b/components/style/properties/longhands/font.mako.rs
index 7f7b66c3572..c1d3d8fcc6c 100644
--- a/components/style/properties/longhands/font.mako.rs
+++ b/components/style/properties/longhands/font.mako.rs
@@ -495,8 +495,7 @@ ${helpers.predefined_type(
         // a lot of code with `if product == gecko` conditionals, we have a
         // dummy system font module that does nothing
 
-        #[derive(Clone, Copy, Debug, Eq, Hash, PartialEq, SpecifiedValueInfo, ToCss)]
-        #[cfg_attr(feature = "servo", derive(MallocSizeOf))]
+        #[derive(Clone, Copy, Debug, Eq, Hash, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToCss, ToShmem)]
         /// void enum for system font, can never exist
         pub enum SystemFont {}
         impl SystemFont {
diff --git a/components/style/servo/selector_parser.rs b/components/style/servo/selector_parser.rs
index 229f7dccdd2..d839654a65a 100644
--- a/components/style/servo/selector_parser.rs
+++ b/components/style/servo/selector_parser.rs
@@ -29,8 +29,7 @@ use style_traits::{ParseError, StyleParseErrorKind};
 /// A pseudo-element, both public and private.
 ///
 /// NB: If you add to this list, be sure to update `each_simple_pseudo_element` too.
-#[derive(Clone, Debug, Eq, Hash, PartialEq)]
-#[cfg_attr(feature = "servo", derive(MallocSizeOf))]
+#[derive(Clone, Debug, Eq, Hash, MallocSizeOf, PartialEq, ToShmem)]
 #[allow(missing_docs)]
 #[repr(usize)]
 pub enum PseudoElement {
@@ -265,8 +264,7 @@ pub type Lang = Box<str>;
 
 /// A non tree-structural pseudo-class.
 /// See https://drafts.csswg.org/selectors-4/#structural-pseudos
-#[derive(Clone, Debug, Eq, Hash, PartialEq)]
-#[cfg_attr(feature = "servo", derive(MallocSizeOf))]
+#[derive(Clone, Debug, Eq, Hash, MallocSizeOf, PartialEq, ToShmem)]
 #[allow(missing_docs)]
 pub enum NonTSPseudoClass {
     Active,
diff --git a/components/style/servo/url.rs b/components/style/servo/url.rs
index 26608de2e29..fd7726289be 100644
--- a/components/style/servo/url.rs
+++ b/components/style/servo/url.rs
@@ -12,7 +12,7 @@ use std::fmt::{self, Write};
 // nonzero optimization is important in keeping the size of SpecifiedUrl below
 // the threshold.
 use crate::values::computed::{Context, ToComputedValue};
-use std::sync::Arc;
+use servo_arc::Arc;
 use style_traits::{CssWriter, ParseError, ToCss};
 
 /// A CSS url() value for servo.
@@ -26,7 +26,7 @@ use style_traits::{CssWriter, ParseError, ToCss};
 ///
 /// TODO(emilio): This should be shrunk by making CssUrl a wrapper type of an
 /// arc, and keep the serialization in that Arc. See gecko/url.rs for example.
-#[derive(Clone, Debug, Deserialize, MallocSizeOf, Serialize, SpecifiedValueInfo)]
+#[derive(Clone, Debug, Deserialize, MallocSizeOf, Serialize, SpecifiedValueInfo, ToShmem)]
 pub struct CssUrl {
     /// The original URI. This might be optional since we may insert computed
     /// values of images into the cascade directly, and we don't bother to
diff --git a/components/style/shared_lock.rs b/components/style/shared_lock.rs
index f5019326ee0..073c696fa3d 100644
--- a/components/style/shared_lock.rs
+++ b/components/style/shared_lock.rs
@@ -15,7 +15,6 @@ use std::cell::UnsafeCell;
 use std::fmt;
 #[cfg(feature = "servo")]
 use std::mem;
-#[cfg(feature = "gecko")]
 use std::mem::ManuallyDrop;
 #[cfg(feature = "gecko")]
 use std::ptr;
@@ -124,11 +123,7 @@ impl<'a> Drop for SharedRwLockReadGuard<'a> {
     fn drop(&mut self) {
         // Unsafe: self.lock is private to this module, only ever set after `read()`,
         // and never copied or cloned (see `compile_time_assert` below).
-        if let Some(arc) = self.0.arc {
-            unsafe {
-                arc.force_unlock_read();
-            }
-        }
+        unsafe { self.0.arc.force_unlock_read() }
     }
 }
 
@@ -166,12 +161,6 @@ impl<T: fmt::Debug> fmt::Debug for Locked<T> {
 }
 
 impl<T> Locked<T> {
-    #[cfg(feature = "servo")]
-    #[inline]
-    fn is_read_only_lock(&self) -> bool {
-        false
-    }
-
     #[cfg(feature = "gecko")]
     #[inline]
     fn is_read_only_lock(&self) -> bool {
@@ -199,10 +188,14 @@ impl<T> Locked<T> {
 
     /// Access the data for reading.
     pub fn read_with<'a>(&'a self, guard: &'a SharedRwLockReadGuard) -> &'a T {
+        #[cfg(feature = "gecko")]
         assert!(
             self.is_read_only_lock() || self.same_lock_as(guard.0.as_ref().map(|r| &**r)),
             "Locked::read_with called with a guard from an unrelated SharedRwLock"
         );
+        #[cfg(not(feature = "gecko"))]
+        assert!(self.same_lock_as(&guard.0));
+
         let ptr = self.data.get();
 
         // Unsafe:
@@ -223,10 +216,14 @@ impl<T> Locked<T> {
 
     /// Access the data for writing.
     pub fn write_with<'a>(&'a self, guard: &'a mut SharedRwLockWriteGuard) -> &'a mut T {
+        #[cfg(feature = "gecko")]
         assert!(
             !self.is_read_only_lock() && self.same_lock_as(Some(&guard.0)),
             "Locked::write_with called with a guard from a read only or unrelated SharedRwLock"
         );
+        #[cfg(not(feature = "gecko"))]
+        assert!(self.same_lock_as(&guard.0));
+
         let ptr = self.data.get();
 
         // Unsafe:
diff --git a/components/style/stylesheets/mod.rs b/components/style/stylesheets/mod.rs
index 133b84fa52f..16842021e8d 100644
--- a/components/style/stylesheets/mod.rs
+++ b/components/style/stylesheets/mod.rs
@@ -39,6 +39,7 @@ use std::fmt;
 #[cfg(feature = "gecko")]
 use std::mem::{self, ManuallyDrop};
 use style_traits::ParsingMode;
+#[cfg(feature = "gecko")]
 use to_shmem::{SharedMemoryBuilder, ToShmem};
 
 pub use self::counter_style_rule::CounterStyleRule;
diff --git a/components/style/values/computed/font.rs b/components/style/values/computed/font.rs
index 001b8444a30..407a547013f 100644
--- a/components/style/values/computed/font.rs
+++ b/components/style/values/computed/font.rs
@@ -29,6 +29,7 @@ use std::mem::{self, ManuallyDrop};
 #[cfg(feature = "servo")]
 use std::slice;
 use style_traits::{CssWriter, ParseError, ToCss};
+#[cfg(feature = "gecko")]
 use to_shmem::{SharedMemoryBuilder, ToShmem};
 
 pub use crate::values::computed::Length as MozScriptMinSize;
@@ -284,7 +285,7 @@ pub enum FontFamilyNameSyntax {
     Identifiers,
 }
 
-#[derive(Clone, Debug, Eq, MallocSizeOf, PartialEq, ToCss, ToResolvedValue)]
+#[derive(Clone, Debug, Eq, MallocSizeOf, PartialEq, ToCss, ToResolvedValue, ToShmem)]
 #[cfg_attr(feature = "servo", derive(Deserialize, Serialize, Hash))]
 /// A set of faces that vary in weight, width or slope.
 pub enum SingleFontFamily {
@@ -299,7 +300,10 @@ pub enum SingleFontFamily {
 /// The order here is important, if you change it make sure that
 /// `gfxPlatformFontList.h`s ranged array and `gfxFontFamilyList`'s
 /// sSingleGenerics are updated as well.
-#[derive(Clone, Copy, Debug, Eq, Hash, MallocSizeOf, PartialEq, Parse, ToCss, ToResolvedValue)]
+#[derive(
+    Clone, Copy, Debug, Eq, Hash, MallocSizeOf, PartialEq, Parse, ToCss, ToResolvedValue, ToShmem,
+)]
+#[cfg_attr(feature = "servo", derive(Deserialize, Serialize))]
 #[repr(u8)]
 #[allow(missing_docs)]
 pub enum GenericFontFamily {
@@ -373,6 +377,35 @@ impl SingleFontFamily {
         }))
     }
 
+    #[cfg(feature = "servo")]
+    /// Get the corresponding font-family with Atom
+    pub fn from_atom(input: Atom) -> SingleFontFamily {
+        match input {
+            atom!("serif") => return SingleFontFamily::Generic(GenericFontFamily::Serif),
+            atom!("sans-serif") => return SingleFontFamily::Generic(GenericFontFamily::SansSerif),
+            atom!("cursive") => return SingleFontFamily::Generic(GenericFontFamily::Cursive),
+            atom!("fantasy") => return SingleFontFamily::Generic(GenericFontFamily::Fantasy),
+            atom!("monospace") => return SingleFontFamily::Generic(GenericFontFamily::Monospace),
+            _ => {},
+        }
+
+        match_ignore_ascii_case! { &input,
+            "serif" => return SingleFontFamily::Generic(GenericFontFamily::Serif),
+            "sans-serif" => return SingleFontFamily::Generic(GenericFontFamily::SansSerif),
+            "cursive" => return SingleFontFamily::Generic(GenericFontFamily::Cursive),
+            "fantasy" => return SingleFontFamily::Generic(GenericFontFamily::Fantasy),
+            "monospace" => return SingleFontFamily::Generic(GenericFontFamily::Monospace),
+            _ => {}
+        }
+
+        // We don't know if it's quoted or not. So we set it to
+        // quoted by default.
+        SingleFontFamily::FamilyName(FamilyName {
+            name: input,
+            syntax: FontFamilyNameSyntax::Quoted,
+        })
+    }
+
     #[cfg(feature = "gecko")]
     /// Get the corresponding font-family with family name
     fn from_font_family_name(family: &structs::FontFamilyName) -> SingleFontFamily {
@@ -389,7 +422,7 @@ impl SingleFontFamily {
 }
 
 #[cfg(feature = "servo")]
-#[derive(Clone, Debug, Eq, Hash, MallocSizeOf, PartialEq, ToResolvedValue)]
+#[derive(Clone, Debug, Eq, Hash, MallocSizeOf, PartialEq, ToResolvedValue, ToShmem)]
 /// A list of SingleFontFamily
 pub struct FontFamilyList(Box<[SingleFontFamily]>);
 
@@ -501,7 +534,7 @@ impl FontFamilyList {
         let mut iter = self.iter();
         if let Some(SingleFontFamily::Generic(f)) = iter.next() {
             if iter.next().is_none() {
-                return Some(f);
+                return Some(f.clone());
             }
         }
         None
diff --git a/components/style/values/generics/grid.rs b/components/style/values/generics/grid.rs
index 393e570f066..d20ba265ab2 100644
--- a/components/style/values/generics/grid.rs
+++ b/components/style/values/generics/grid.rs
@@ -557,7 +557,7 @@ pub enum TrackListType {
 /// A grid `<track-list>` type.
 ///
 /// <https://drafts.csswg.org/css-grid/#typedef-track-list>
-#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToShmem, ToResolvedValue)]
+#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToResolvedValue, ToShmem)]
 pub struct TrackList<LengthPercentage, Integer> {
     /// The type of this `<track-list>` (auto, explicit or general).
     ///
diff --git a/components/style/values/generics/image.rs b/components/style/values/generics/image.rs
index a7fa6da9337..71d6a1b3849 100644
--- a/components/style/values/generics/image.rs
+++ b/components/style/values/generics/image.rs
@@ -157,7 +157,7 @@ pub struct ColorStop<Color, LengthPercentage> {
 /// Specified values for a paint worklet.
 /// <https://drafts.css-houdini.org/css-paint-api/>
 #[cfg_attr(feature = "servo", derive(MallocSizeOf))]
-#[derive(Clone, Debug, PartialEq, ToComputedValue)]
+#[derive(Clone, Debug, PartialEq, ToComputedValue, ToResolvedValue, ToShmem)]
 pub struct PaintWorklet {
     /// The name the worklet was registered with.
     pub name: Atom,
diff --git a/components/style/values/resolved/mod.rs b/components/style/values/resolved/mod.rs
index 7877ed71a0b..4003060148c 100644
--- a/components/style/values/resolved/mod.rs
+++ b/components/style/values/resolved/mod.rs
@@ -65,15 +65,16 @@ trivial_to_resolved_value!(u8);
 trivial_to_resolved_value!(i8);
 trivial_to_resolved_value!(u16);
 trivial_to_resolved_value!(u32);
-#[cfg(feature = "servo")]
-trivial_to_resolved_value!(Prefix);
 trivial_to_resolved_value!(String);
 trivial_to_resolved_value!(Box<str>);
 trivial_to_resolved_value!(cssparser::RGBA);
 trivial_to_resolved_value!(crate::Atom);
 trivial_to_resolved_value!(app_units::Au);
 trivial_to_resolved_value!(computed::url::ComputedUrl);
+#[cfg(feature = "gecko")]
 trivial_to_resolved_value!(computed::url::ComputedImageUrl);
+#[cfg(feature = "servo")]
+trivial_to_resolved_value!(html5ever::Prefix);
 
 impl<A, B> ToResolvedValue for (A, B)
 where
diff --git a/components/style/values/specified/font.rs b/components/style/values/specified/font.rs
index f02d44124a2..127b1bfc2fb 100644
--- a/components/style/values/specified/font.rs
+++ b/components/style/values/specified/font.rs
@@ -1192,7 +1192,7 @@ macro_rules! impl_variant_east_asian {
         )+
     } => {
         bitflags! {
-            #[derive(MallocSizeOf, ToShmem, ToResolvedValue)]
+            #[derive(MallocSizeOf, ToResolvedValue, ToShmem)]
             /// Vairants for east asian variant
             pub struct VariantEastAsian: u16 {
                 /// None of the features
diff --git a/components/to_shmem/Cargo.toml b/components/to_shmem/Cargo.toml
index bebc45e821d..2e7b06eaaca 100644
--- a/components/to_shmem/Cargo.toml
+++ b/components/to_shmem/Cargo.toml
@@ -10,13 +10,14 @@ name = "to_shmem"
 path = "lib.rs"
 
 [features]
-servo = ["serde", "cssparser/serde"]
+servo = ["serde", "cssparser/serde", "string_cache"]
 gecko = []
 
 [dependencies]
 cssparser = "0.25"
-serde = {version = "1.0", optional = true}
+serde = { version = "1.0", optional = true }
 servo_arc = { path = "../servo_arc" }
 smallbitvec = "2.1.1"
 smallvec = "0.6.6"
+string_cache = { version = "0.7", optional = true }
 thin-slice = "0.1.0"
diff --git a/components/to_shmem/lib.rs b/components/to_shmem/lib.rs
index 59fc2afb546..96dfbb3a5e9 100644
--- a/components/to_shmem/lib.rs
+++ b/components/to_shmem/lib.rs
@@ -16,6 +16,8 @@ extern crate cssparser;
 extern crate servo_arc;
 extern crate smallbitvec;
 extern crate smallvec;
+#[cfg(feature = "string_cache")]
+extern crate string_cache;
 extern crate thin_slice;
 
 use servo_arc::{Arc, ThinArc};
@@ -193,16 +195,18 @@ pub trait ToShmem: Sized {
 
 #[macro_export]
 macro_rules! impl_trivial_to_shmem {
-    ($($ty:ty),*) => {$(
-        impl $crate::ToShmem for $ty {
-            fn to_shmem(
-                &self,
-                _builder: &mut $crate::SharedMemoryBuilder,
-            ) -> ::std::mem::ManuallyDrop<Self> {
-                ::std::mem::ManuallyDrop::new(*self)
+    ($($ty:ty),*) => {
+        $(
+            impl $crate::ToShmem for $ty {
+                fn to_shmem(
+                    &self,
+                    _builder: &mut $crate::SharedMemoryBuilder,
+                ) -> ::std::mem::ManuallyDrop<Self> {
+                    ::std::mem::ManuallyDrop::new(*self)
+                }
             }
-        }
-    )*};
+        )*
+    };
 }
 
 impl_trivial_to_shmem!(
@@ -522,3 +526,17 @@ impl ToShmem for SmallBitVec {
         ManuallyDrop::new(unsafe { SmallBitVec::from_storage(storage) })
     }
 }
+
+#[cfg(feature = "string_cache")]
+impl<Static: string_cache::StaticAtomSet> ToShmem for string_cache::Atom<Static> {
+    fn to_shmem(&self, _: &mut SharedMemoryBuilder) -> ManuallyDrop<Self> {
+        // NOTE(emilio): In practice, this can be implemented trivially if
+        // string_cache could expose the implementation detail of static atoms
+        // being an index into the static table (and panicking in the
+        // non-static, non-inline cases).
+        unimplemented!(
+            "If servo wants to share stylesheets across processes, \
+             then ToShmem for Atom needs to be implemented"
+        )
+    }
+}
diff --git a/components/to_shmem_derive/to_shmem.rs b/components/to_shmem_derive/to_shmem.rs
index 1335ef4eea6..e7ff8c29b8c 100644
--- a/components/to_shmem_derive/to_shmem.rs
+++ b/components/to_shmem_derive/to_shmem.rs
@@ -40,7 +40,7 @@ pub fn derive(mut input: syn::DeriveInput) -> TokenStream {
 
     quote! {
         impl #impl_generics ::to_shmem::ToShmem for #name #ty_generics #where_clause {
-            #[allow(unused_variables)]
+            #[allow(unused_variables, unreachable_code)]
             fn to_shmem(
                 &self,
                 builder: &mut ::to_shmem::SharedMemoryBuilder,
diff --git a/components/url/Cargo.toml b/components/url/Cargo.toml
index dbbed4f58db..1a59812e071 100644
--- a/components/url/Cargo.toml
+++ b/components/url/Cargo.toml
@@ -13,6 +13,8 @@ path = "lib.rs"
 [dependencies]
 malloc_size_of = { path = "../malloc_size_of", features = ["servo"] }
 malloc_size_of_derive = "0.1"
+to_shmem = { path = "../to_shmem" }
+to_shmem_derive = { path = "../to_shmem_derive" }
 serde = {version = "1.0", features = ["derive"]}
 servo_rand = {path = "../rand"}
 url = "1.2"
diff --git a/components/url/lib.rs b/components/url/lib.rs
index dccd27a8b00..bb7c1fa4e35 100644
--- a/components/url/lib.rs
+++ b/components/url/lib.rs
@@ -20,10 +20,12 @@ pub use crate::origin::{ImmutableOrigin, MutableOrigin, OpaqueOrigin};
 use std::collections::hash_map::DefaultHasher;
 use std::fmt;
 use std::hash::Hasher;
+use std::mem::ManuallyDrop;
 use std::net::IpAddr;
 use std::ops::{Index, Range, RangeFrom, RangeFull, RangeTo};
 use std::path::Path;
 use std::sync::Arc;
+use to_shmem::{SharedMemoryBuilder, ToShmem};
 use url::{Position, Url};
 
 pub use url::Host;
@@ -31,6 +33,12 @@ pub use url::Host;
 #[derive(Clone, Eq, Hash, MallocSizeOf, Ord, PartialEq, PartialOrd)]
 pub struct ServoUrl(#[ignore_malloc_size_of = "Arc"] Arc<Url>);
 
+impl ToShmem for ServoUrl {
+    fn to_shmem(&self, _builder: &mut SharedMemoryBuilder) -> ManuallyDrop<Self> {
+        unimplemented!("If servo wants to share stylesheets across processes, ToShmem for Url must be implemented")
+    }
+}
+
 impl ServoUrl {
     pub fn from_url(url: Url) -> Self {
         ServoUrl(Arc::new(url))

From 34ad6150c8866ccc114987465abbcdf19c8d820f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Emilio=20Cobos=20=C3=81lvarez?= <emilio@crisal.io>
Date: Fri, 12 Apr 2019 02:13:26 +0200
Subject: [PATCH 57/59] Remove an unused extern crate.

---
 components/derive_common/lib.rs | 1 -
 1 file changed, 1 deletion(-)

diff --git a/components/derive_common/lib.rs b/components/derive_common/lib.rs
index 1e8d20aa32d..14415351449 100644
--- a/components/derive_common/lib.rs
+++ b/components/derive_common/lib.rs
@@ -3,7 +3,6 @@
  * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
 
 extern crate darling;
-extern crate proc_macro;
 extern crate proc_macro2;
 #[macro_use]
 extern crate quote;

From a1d224b8235e0eb72573655715a74d8b5c0e68d5 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Emilio=20Cobos=20=C3=81lvarez?= <emilio@crisal.io>
Date: Fri, 12 Apr 2019 12:16:13 +0200
Subject: [PATCH 58/59] Remove style system serialization tests that are tested
 via wpt.

---
 tests/unit/style/properties/mod.rs           |  65 ----
 tests/unit/style/properties/serialization.rs | 353 -------------------
 2 files changed, 418 deletions(-)
 delete mode 100644 tests/unit/style/properties/serialization.rs

diff --git a/tests/unit/style/properties/mod.rs b/tests/unit/style/properties/mod.rs
index 06a5c2086f4..26a702ac07f 100644
--- a/tests/unit/style/properties/mod.rs
+++ b/tests/unit/style/properties/mod.rs
@@ -2,69 +2,4 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
 
-use cssparser::{Parser, ParserInput};
-use style::context::QuirksMode;
-use style::parser::ParserContext;
-use style::stylesheets::{CssRuleType, Origin};
-use style_traits::{ParseError, ParsingMode};
-
-fn parse<T, F>(f: F, s: &'static str) -> Result<T, ParseError<'static>>
-where
-    F: for<'t> Fn(&ParserContext, &mut Parser<'static, 't>) -> Result<T, ParseError<'static>>,
-{
-    let mut input = ParserInput::new(s);
-    parse_input(f, &mut input)
-}
-
-fn parse_input<'i: 't, 't, T, F>(f: F, input: &'t mut ParserInput<'i>) -> Result<T, ParseError<'i>>
-where
-    F: Fn(&ParserContext, &mut Parser<'i, 't>) -> Result<T, ParseError<'i>>,
-{
-    let url = ::servo_url::ServoUrl::parse("http://localhost").unwrap();
-    let context = ParserContext::new(
-        Origin::Author,
-        &url,
-        Some(CssRuleType::Style),
-        ParsingMode::DEFAULT,
-        QuirksMode::NoQuirks,
-        None,
-        None,
-    );
-    let mut parser = Parser::new(input);
-    f(&context, &mut parser)
-}
-
-macro_rules! assert_roundtrip_with_context {
-    ($fun:expr, $string:expr) => {
-        assert_roundtrip_with_context!($fun, $string, $string);
-    };
-    ($fun:expr, $input:expr, $output:expr) => {{
-        let serialized = parse(
-            |context, i| {
-                let parsed = $fun(context, i).expect(&format!("Failed to parse {}", $input));
-                let serialized = ToCss::to_css_string(&parsed);
-                assert_eq!(serialized, $output);
-                Ok(serialized)
-            },
-            $input,
-        )
-        .unwrap();
-
-        let mut input = ::cssparser::ParserInput::new(&serialized);
-        let unwrapped = parse_input(
-            |context, i| {
-                let re_parsed =
-                    $fun(context, i).expect(&format!("Failed to parse serialization {}", $input));
-                let re_serialized = ToCss::to_css_string(&re_parsed);
-                assert_eq!(serialized, re_serialized);
-                Ok(())
-            },
-            &mut input,
-        )
-        .unwrap();
-        unwrapped
-    }};
-}
-
 mod scaffolding;
-mod serialization;
diff --git a/tests/unit/style/properties/serialization.rs b/tests/unit/style/properties/serialization.rs
deleted file mode 100644
index 8853ab010dd..00000000000
--- a/tests/unit/style/properties/serialization.rs
+++ /dev/null
@@ -1,353 +0,0 @@
-/* This Source Code Form is subject to the terms of the Mozilla Public
- * License, v. 2.0. If a copy of the MPL was not distributed with this
- * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
-
-use crate::properties::{parse, parse_input};
-use crate::stylesheets::block_from;
-use style::properties::declaration_block::PropertyDeclarationBlock;
-use style::properties::parse_property_declaration_list;
-use style::properties::{Importance, PropertyDeclaration};
-use style::values::specified::url::SpecifiedUrl;
-use style::values::specified::Length;
-use style_traits::ToCss;
-
-trait ToCssString {
-    fn to_css_string(&self) -> String;
-}
-
-impl ToCssString for PropertyDeclarationBlock {
-    fn to_css_string(&self) -> String {
-        let mut css = String::new();
-        self.to_css(&mut css).unwrap();
-        css
-    }
-}
-
-mod shorthand_serialization {
-    pub use super::*;
-
-    pub fn shorthand_properties_to_string(properties: Vec<PropertyDeclaration>) -> String {
-        let block = block_from(properties.into_iter().map(|d| (d, Importance::Normal)));
-
-        block.to_css_string()
-    }
-
-    mod list_style {
-        use super::*;
-        use style::properties::longhands::list_style_position::SpecifiedValue as ListStylePosition;
-        use style::properties::longhands::list_style_type::SpecifiedValue as ListStyleType;
-        use style::values::generics::url::UrlOrNone as ImageUrlOrNone;
-
-        #[test]
-        fn list_style_should_show_all_properties_when_values_are_set() {
-            let mut properties = Vec::new();
-
-            let position = ListStylePosition::Inside;
-            let image = ImageUrlOrNone::Url(SpecifiedUrl::new_for_testing("http://servo/test.png"));
-            let style_type = ListStyleType::Disc;
-
-            properties.push(PropertyDeclaration::ListStylePosition(position));
-
-            #[cfg(feature = "gecko")]
-            properties.push(PropertyDeclaration::ListStyleImage(Box::new(image)));
-            #[cfg(not(feature = "gecko"))]
-            properties.push(PropertyDeclaration::ListStyleImage(image));
-
-            properties.push(PropertyDeclaration::ListStyleType(style_type));
-
-            let serialization = shorthand_properties_to_string(properties);
-            assert_eq!(
-                serialization,
-                "list-style: inside url(\"http://servo/test.png\") disc;"
-            );
-        }
-    }
-
-    mod background {
-        use super::*;
-
-        #[test]
-        fn background_should_serialize_all_available_properties_when_specified() {
-            let block_text = "\
-                              background-color: rgb(255, 0, 0); \
-                              background-image: url(\"http://servo/test.png\"); \
-                              background-repeat: repeat-x; \
-                              background-attachment: scroll; \
-                              background-size: 70px 50px; \
-                              background-position-x: 7px; \
-                              background-position-y: bottom 4px; \
-                              background-origin: border-box; \
-                              background-clip: padding-box;";
-
-            let block =
-                parse(|c, i| Ok(parse_property_declaration_list(c, i)), block_text).unwrap();
-
-            let serialization = block.to_css_string();
-
-            assert_eq!(
-                serialization,
-                "background: rgb(255, 0, 0) url(\"http://servo/test.png\") repeat-x \
-                 scroll left 7px bottom 4px / 70px 50px border-box padding-box;"
-            );
-        }
-
-        #[test]
-        fn background_should_combine_origin_and_clip_properties_when_equal() {
-            let block_text = "\
-                              background-color: rgb(255, 0, 0); \
-                              background-image: url(\"http://servo/test.png\"); \
-                              background-repeat: repeat-x; \
-                              background-attachment: scroll; \
-                              background-size: 70px 50px; \
-                              background-position-x: 7px; \
-                              background-position-y: 4px; \
-                              background-origin: padding-box; \
-                              background-clip: padding-box;";
-
-            let block =
-                parse(|c, i| Ok(parse_property_declaration_list(c, i)), block_text).unwrap();
-
-            let serialization = block.to_css_string();
-
-            assert_eq!(
-                serialization,
-                "background: rgb(255, 0, 0) url(\"http://servo/test.png\") repeat-x \
-                 scroll 7px 4px / 70px 50px padding-box;"
-            );
-        }
-
-        #[test]
-        fn serialize_multiple_backgrounds() {
-            let block_text = "\
-                              background-color: rgb(0, 0, 255); \
-                              background-image: url(\"http://servo/test.png\"), none; \
-                              background-repeat: repeat-x, repeat-y; \
-                              background-attachment: scroll, scroll; \
-                              background-size: 70px 50px, 20px 30px; \
-                              background-position-x: 7px, 70px; \
-                              background-position-y: 4px, 40px; \
-                              background-origin: border-box, padding-box; \
-                              background-clip: padding-box, padding-box;";
-
-            let block =
-                parse(|c, i| Ok(parse_property_declaration_list(c, i)), block_text).unwrap();
-
-            let serialization = block.to_css_string();
-
-            assert_eq!(
-                serialization, "background: \
-                url(\"http://servo/test.png\") repeat-x scroll 7px 4px / 70px 50px border-box padding-box, \
-                rgb(0, 0, 255) none repeat-y scroll 70px 40px / 20px 30px padding-box;"
-            );
-        }
-
-        #[test]
-        fn serialize_multiple_backgrounds_unequal_property_lists() {
-            // When the lengths of property values are different, the shorthand serialization
-            // should not be used. Previously the implementation cycled values if the lists were
-            // uneven. This is incorrect, in that we should serialize to a shorthand only when the
-            // lists have the same length (this affects background, transition and animation).
-            // https://github.com/servo/servo/issues/15398 )
-            // With background, the color is one exception as it should only appear once for
-            // multiple backgrounds.
-            // Below background-origin only has one value.
-            let block_text = "\
-                              background-color: rgb(0, 0, 255); \
-                              background-image: url(\"http://servo/test.png\"), none; \
-                              background-repeat: repeat-x, repeat-y; \
-                              background-attachment: scroll, scroll; \
-                              background-size: 70px 50px, 20px 30px; \
-                              background-position: 7px 4px, 5px 6px; \
-                              background-origin: border-box; \
-                              background-clip: padding-box, padding-box;";
-
-            let block =
-                parse(|c, i| Ok(parse_property_declaration_list(c, i)), block_text).unwrap();
-
-            let serialization = block.to_css_string();
-
-            assert_eq!(serialization, block_text);
-        }
-
-        #[test]
-        fn background_position_should_be_a_valid_form_its_longhands() {
-            // If there is any longhand consisted of both keyword and position,
-            // the shorthand result should be the 4-value format.
-            let block_text = "\
-                              background-position-x: 30px;\
-                              background-position-y: bottom 20px;";
-            let block =
-                parse(|c, i| Ok(parse_property_declaration_list(c, i)), block_text).unwrap();
-            let serialization = block.to_css_string();
-            assert_eq!(serialization, "background-position: left 30px bottom 20px;");
-
-            // If there is no longhand consisted of both keyword and position,
-            // the shorthand result should be the 2-value format.
-            let block_text = "\
-                              background-position-x: center;\
-                              background-position-y: 20px;";
-            let block =
-                parse(|c, i| Ok(parse_property_declaration_list(c, i)), block_text).unwrap();
-            let serialization = block.to_css_string();
-            assert_eq!(serialization, "background-position: center 20px;");
-        }
-    }
-
-    mod quotes {
-        pub use super::*;
-
-        #[test]
-        fn should_serialize_none_correctly() {
-            use style::properties::longhands::quotes;
-
-            assert_roundtrip_with_context!(quotes::parse, "none");
-        }
-    }
-
-    mod animation {
-        pub use super::*;
-
-        #[test]
-        fn serialize_single_animation() {
-            let block_text = "\
-                              animation-name: bounce;\
-                              animation-duration: 1s;\
-                              animation-timing-function: ease-in;\
-                              animation-delay: 0s;\
-                              animation-direction: normal;\
-                              animation-fill-mode: forwards;\
-                              animation-iteration-count: infinite;\
-                              animation-play-state: paused;";
-
-            let block =
-                parse(|c, i| Ok(parse_property_declaration_list(c, i)), block_text).unwrap();
-
-            let serialization = block.to_css_string();
-
-            assert_eq!(
-                serialization,
-                "animation: 1s ease-in 0s infinite normal forwards paused bounce;"
-            )
-        }
-
-        #[test]
-        fn serialize_multiple_animations() {
-            let block_text = "\
-                              animation-name: bounce, roll;\
-                              animation-duration: 1s, 0.2s;\
-                              animation-timing-function: ease-in, linear;\
-                              animation-delay: 0s, 1s;\
-                              animation-direction: normal, reverse;\
-                              animation-fill-mode: forwards, backwards;\
-                              animation-iteration-count: infinite, 2;\
-                              animation-play-state: paused, running;";
-
-            let block =
-                parse(|c, i| Ok(parse_property_declaration_list(c, i)), block_text).unwrap();
-
-            let serialization = block.to_css_string();
-
-            assert_eq!(
-                serialization,
-                "animation: 1s ease-in 0s infinite normal forwards paused bounce, \
-                 0.2s linear 1s 2 reverse backwards running roll;"
-            );
-        }
-
-        #[test]
-        fn serialize_multiple_animations_unequal_property_lists() {
-            // When the lengths of property values are different, the shorthand serialization
-            // should not be used. Previously the implementation cycled values if the lists were
-            // uneven. This is incorrect, in that we should serialize to a shorthand only when the
-            // lists have the same length (this affects background, transition and animation).
-            // https://github.com/servo/servo/issues/15398 )
-            let block_text = "\
-                              animation-name: bounce, roll, flip, jump; \
-                              animation-duration: 1s, 0.2s; \
-                              animation-timing-function: ease-in, linear; \
-                              animation-delay: 0s, 1s, 0.5s; \
-                              animation-direction: normal; \
-                              animation-fill-mode: forwards, backwards; \
-                              animation-iteration-count: infinite, 2; \
-                              animation-play-state: paused, running;";
-
-            let block =
-                parse(|c, i| Ok(parse_property_declaration_list(c, i)), block_text).unwrap();
-
-            let serialization = block.to_css_string();
-
-            assert_eq!(serialization, block_text);
-        }
-
-        #[test]
-        fn serialize_multiple_without_all_properties_returns_longhand() {
-            // timing function and direction are missing, so no shorthand is returned.
-            let block_text = "animation-name: bounce, roll; \
-                              animation-duration: 1s, 0.2s; \
-                              animation-delay: 0s, 1s; \
-                              animation-fill-mode: forwards, backwards; \
-                              animation-iteration-count: infinite, 2; \
-                              animation-play-state: paused, running;";
-
-            let block =
-                parse(|c, i| Ok(parse_property_declaration_list(c, i)), block_text).unwrap();
-
-            let serialization = block.to_css_string();
-
-            assert_eq!(serialization, block_text);
-        }
-    }
-
-    mod keywords {
-        pub use super::*;
-        #[test]
-        fn css_wide_keywords_should_be_parsed() {
-            let block_text = "--a:inherit;";
-            let block =
-                parse(|c, i| Ok(parse_property_declaration_list(c, i)), block_text).unwrap();
-
-            let serialization = block.to_css_string();
-            assert_eq!(serialization, "--a: inherit;");
-        }
-
-        #[test]
-        fn non_keyword_custom_property_should_be_unparsed() {
-            let block_text = "--main-color: #06c;";
-            let block =
-                parse(|c, i| Ok(parse_property_declaration_list(c, i)), block_text).unwrap();
-
-            let serialization = block.to_css_string();
-            assert_eq!(serialization, block_text);
-        }
-    }
-
-    mod effects {
-        pub use super::*;
-        pub use style::properties::longhands::box_shadow::SpecifiedValue as BoxShadowList;
-        pub use style::values::specified::effects::{BoxShadow, SimpleShadow};
-
-        #[test]
-        fn box_shadow_should_serialize_correctly() {
-            use style::values::specified::length::NonNegativeLength;
-
-            let mut properties = Vec::new();
-            let shadow_val = BoxShadow {
-                base: SimpleShadow {
-                    color: None,
-                    horizontal: Length::from_px(1f32),
-                    vertical: Length::from_px(2f32),
-                    blur: Some(NonNegativeLength::from_px(3f32)),
-                },
-                spread: Some(Length::from_px(4f32)),
-                inset: false,
-            };
-            let shadow_decl = BoxShadowList(vec![shadow_val]);
-            properties.push(PropertyDeclaration::BoxShadow(shadow_decl));
-            let shadow_css = "box-shadow: 1px 2px 3px 4px;";
-            let shadow =
-                parse(|c, i| Ok(parse_property_declaration_list(c, i)), shadow_css).unwrap();
-
-            assert_eq!(shadow.to_css_string(), shadow_css);
-        }
-    }
-}

From 63778555268b8b4904dcfc24a0a0c91dcb395074 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Emilio=20Cobos=20=C3=81lvarez?= <emilio@crisal.io>
Date: Fri, 12 Apr 2019 12:19:15 +0200
Subject: [PATCH 59/59] Fix gfx unit tests.

---
 components/gfx/tests/font_context.rs | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/components/gfx/tests/font_context.rs b/components/gfx/tests/font_context.rs
index 3a3f73671ac..4752a5fb3b3 100644
--- a/components/gfx/tests/font_context.rs
+++ b/components/gfx/tests/font_context.rs
@@ -20,7 +20,7 @@ use std::rc::Rc;
 use style::properties::longhands::font_variant_caps::computed_value::T as FontVariantCaps;
 use style::properties::style_structs::Font as FontStyleStruct;
 use style::values::computed::font::{
-    FamilyName, FamilyNameSyntax, FontFamily, FontFamilyList, FontSize,
+    FamilyName, FontFamily, FontFamilyList, FontFamilyNameSyntax, FontSize,
 };
 use style::values::computed::font::{FontStretch, FontWeight, SingleFontFamily};
 use style::values::generics::font::FontStyle;
@@ -114,7 +114,7 @@ fn font_family(names: Vec<&str>) -> FontFamily {
         .map(|name| {
             SingleFontFamily::FamilyName(FamilyName {
                 name: Atom::from(name),
-                syntax: FamilyNameSyntax::Quoted,
+                syntax: FontFamilyNameSyntax::Quoted,
             })
         })
         .collect();